* internal/ethapi: return revert reason for eth_call

* internal/ethapi: moved revert reason logic to doCall

* accounts/abi/bind/backends: added revert reason logic to simulated backend

* internal/ethapi: fixed linting error

* internal/ethapi: check if require reason can be unpacked

* internal/ethapi: better error logic

* internal/ethapi: simplify logic

* internal/ethapi: return vmError()

* internal/ethapi: move handling of revert out of docall

* graphql: removed revert logic until spec change

* rpc: internal/ethapi: added custom error types

* graphql: use returndata instead of return

Return() checks if there is an error. If an error is found, we return nil.
For most use cases it can be beneficial to return the output even if there
was an error. This code should be changed anyway once the spec supports
error reasons in graphql responses

* accounts/abi/bind/backends: added tests for revert reason

* internal/ethapi: add errorCode to revert error

* internal/ethapi: add errorCode of 3 to revertError

* internal/ethapi: unified estimateGasErrors, simplified logic

* internal/ethapi: unified handling of errors in DoEstimateGas

* rpc: print error data field

* accounts/abi/bind/backends: unify simulatedBackend and RPC

* internal/ethapi: added binary data to revertError data

* internal/ethapi: refactored unpacking logic into newRevertError

* accounts/abi/bind/backends: fix EstimateGas

* accounts, console, internal, rpc: minor error interface cleanups

* Revert "accounts, console, internal, rpc: minor error interface cleanups"

This reverts commit 2d3ef53c5304e429a04983210a417c1f4e0dafb7.

* re-apply the good parts of 2d3ef53c53

* rpc: add test for returning server error data from client

Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
Co-authored-by: Péter Szilágyi <peterke@gmail.com>
Co-authored-by: Felix Lange <fjl@twurst.com>
# Conflicts:
#	accounts/abi/bind/backends/simulated.go
#	accounts/abi/bind/backends/simulated_test.go

* rpc: send websocket ping when connection is idle

* rpc: use non-blocking send for websocket pingReset

# Conflicts:
#	accounts/abi/bind/backends/simulated.go
#	cmd/puppeth/module_dashboard.go
#	core/blockchain_test.go
#	core/rawdb/chain_iterator.go
#	core/state/snapshot/difflayer.go
#	core/state/snapshot/iterator.go
#	core/state/snapshot/iterator_fast.go
#	core/state/snapshot/snapshot.go
#	core/state/snapshot/wipe.go
#	core/tx_pool.go
#	les/clientpool.go
#	les/peer.go
#	mobile/doc.go
#	trie/committer.go
#	trie/database.go

This corrects the call to eth_getBlockByNumber, which previously
returned this error:

  can't get latest block: missing value for required argument 1

Co-authored-by: Felix Lange <fjl@twurst.com>
# Conflicts:
#	rpc/client_example_test.go

* core: initial version of state snapshots

* core/state: lazy sorting, snapshot invalidation

* core/state/snapshot: extract and split cap method, cover corners

* snapshot: iteration and buffering optimizations

* core/state/snapshot: unlink snapshots from blocks, quad->linear cleanup

* 123

* core/rawdb, core/state/snapshot: runtime snapshot generation

* core/state/snapshot: fix difflayer origin-initalization after flatten

* add "to merge"

* core/state/snapshot: implement snapshot layer iteration

* core/state/snapshot: node behavioural difference on bloom content

* core: journal the snapshot inside leveldb, not a flat file

* core/state/snapshot: bloom, metrics and prefetcher fixes

* core/state/snapshot: move iterator out into its own files

* core/state/snapshot: implement iterator priority for fast direct data lookup

* core/state/snapshot: full featured account iteration

* core/state/snapshot: faster account iteration, CLI integration

* core: fix broken tests due to API changes + linter

* core/state: fix an account resurrection issue

* core/tests: test for destroy+recreate contract with storage

* squashme

* core/state/snapshot, tests: sync snap gen + snaps in consensus tests

* core/state: extend snapshotter to handle account resurrections

* core/state: fix account root hash update point

* core/state: fix resurrection state clearing and access

* core/state/snapshot: handle deleted accounts in fast iterator

* core: more blockchain tests

* core/state/snapshot: fix various iteration issues due to destruct set

* core: fix two snapshot iterator flaws, decollide snap storage prefix

* core/state/snapshot/iterator: fix two disk iterator flaws

* core/rawdb: change SnapshotStoragePrefix to avoid prefix collision with preimagePrefix

* params: begin v1.9.13 release cycle

* cmd/checkpoint-admin: add some documentation (#20697)

* go.mod: update duktape to fix sprintf warnings (#20777)

This revision of go-duktype fixes the following warning

```
duk_logging.c: In function ‘duk__logger_prototype_log_shared’:
duk_logging.c:184:64: warning: ‘Z’ directive writing 1 byte into a region of size between 0 and 9 [-Wformat-overflow=]
  184 |  sprintf((char *) date_buf, "%04d-%02d-%02dT%02d:%02d:%02d.%03dZ",
      |                                                                ^
In file included from /usr/include/stdio.h:867,
                 from duk_logging.c:5:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:36:10: note: ‘__builtin___sprintf_chk’ output between 25 and 85 bytes into a destination of size 32
   36 |   return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   37 |       __bos (__s), __fmt, __va_arg_pack ());
      |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```

* core/rawdb: fix freezer table test error check

Fixes: Condition is always 'false' because 'err' is always 'nil'

* core/rawdb: improve table database (#20703)

This PR fixes issues in TableDatabase.

TableDatabase is a wrapper of underlying ethdb.Database with an additional prefix.
The prefix is applied to all entries it maintains. However when we try to retrieve entries
from it we don't handle the key properly. In theory the prefix should be truncated and
only user key is returned. But we don't do it in some cases, e.g. the iterator and batch
replayer created from it. So this PR is the fix to these issues.

* eth: when triggering a sync, check the head header TD, not block

* internal/web3ext: fix clique console apis to work on missing arguments

* rpc: dont log an error if user configures --rpcapi=rpc... (#20776)

This just prevents a false negative ERROR warning when, for some unknown
reason, a user attempts to turn on the module rpc even though it's already going
to be on.

* node, cmd/clef: report actual port used for http rpc (#20789)

* internal/ethapi: don't set sender-balance to maxuint, fixes #16999 (#20783)

Prior to this change, eth_call changed the balance of the sender account in the
EVM environment to 2^256 wei to cover the gas cost of the call execution.
We've had this behavior for a long time even though it's super confusing.

This commit sets the default call gasprice to zero instead of updating the balance,
which is better because it makes eth_call semantics less surprising. Removing
the built-in balance assignment also makes balance overrides work as expected.

* metrics: disable CPU stats (gosigar) on iOS

* cmd/devp2p: tweak DNS TTLs (#20801)

* cmd/devp2p: tweak DNS TTLs

* cmd/devp2p: bump treeNodeTTL to four weeks

* cmd/devp2p: lower route53 change limit again (#20819)

* cmd/devp2p: be very correct about route53 change splitting (#20820)

Turns out the way RDATA limits work is documented after all,
I just didn't search right. The trick to make it work is to
count UPSERTs twice.

This also adds an additional check to ensure TTL changes are
applied on existing records.

* graphql, node, rpc: fix typos in comments (#20824)

* eth: improve shutdown synchronization (#20695)

* eth: improve shutdown synchronization

Most goroutines started by eth.Ethereum didn't have any shutdown sync at
all, which lead to weird error messages when quitting the client.

This change improves the clean shutdown path by stopping all internal
components in dependency order and waiting for them to actually be
stopped before shutdown is considered done. In particular, we now stop
everything related to peers before stopping 'resident' parts such as
core.BlockChain.

* eth: rewrite sync controller

* eth: remove sync start debug message

* eth: notify chainSyncer about new peers after handshake

* eth: move downloader.Cancel call into chainSyncer

* eth: make post-sync block broadcast synchronous

* eth: add comments

* core: change blockchain stop message

* eth: change closeBloomHandler channel type

* eth/filters: fix typo on unindexedLogs function's comment (#20827)

* core: bump txpool tx max size to 128KB

* snapshotter/tests: verify snapdb post-state against trie (#20812)

* core/state/snapshot: basic trie-to-hash implementation

* tests: validate snapshot after test

* core/state/snapshot: fix review concerns

* cmd, consensus: add option to disable mmap for DAG caches/datasets (#20484)

* cmd, consensus: add option to disable mmap for DAG caches/datasets

* consensus: add benchmarks for mmap with/with lock

* cmd/clef: add newaccount command (#20782)

* cmd/clef: add newaccount command

* cmd/clef: document clef_New, update API versioning

* Update cmd/clef/intapi_changelog.md

Co-Authored-By: ligi <ligi@ligi.de>

* Update signer/core/uiapi.go

Co-Authored-By: ligi <ligi@ligi.de>

Co-authored-by: ligi <ligi@ligi.de>

* eth: add debug_accountRange API (#19645)

This new API allows reading accounts and their content by address range.

Co-authored-by: Martin Holst Swende <martin@swende.se>
Co-authored-by: Felix Lange <fjl@twurst.com>

* travis: allow cocoapods deploy to fail (#20833)

* metrics: improve TestTimerFunc (#20818)

The test failed due to what appears to be fluctuations in time.Sleep, which is
not the actual method under test. This change modifies it so we compare the
metered Max to the actual time instead of the desired time.

* README: update private network genesis spec with istanbul (#20841)

* add istanbul and muirGlacier to genesis states in README

* remove muirGlacier, relocate istanbul

* cmd/evm: Rework execution stats (#20792)

- Dump stats also for --bench flag.
- From memory stats only show number and size of allocations. This is what `test -bench` shows. I doubt others like number of GC runs are any useful, but can be added if requested.
- Now the mem stats are for single execution in case of --bench.

* cmd/devp2p, cmd/wnode, whisper: add missing calls to Timer.Stop (#20843)

* p2p/server: add UDP port mapping goroutine to wait group (#20846)

* accounts/abi faster unpacking of int256 (#20850)

* p2p/discv5: add missing Timer.Stop calls (#20853)

* miner/worker: add missing timer.Stop call (#20857)

* cmd/geth: fix bad genesis test (#20860)

* eth/filters: add missing Ticker.Stop call (#20862)

* eth/fetcher: add missing timer.Stop calls (#20861)

* event: add missing timer.Stop call in TestFeed (#20868)

* metrics: add missing calls to Ticker.Stop in tests (#20866)

* ethstats: add missing Ticker.Stop call (#20867)

* p2p/discv5, p2p/testing: add missing Timer.Stop calls in tests (#20869)

* core: add missing Timer.Stop call in TestLogReorgs (#20870)

* rpc: add missing timer.Stop calls in websocket tests (#20863)

* crypto/ecies: improve concatKDF (#20836)

This removes a bunch of weird code around the counter overflow check in
concatKDF and makes it actually work for different hash output sizes.

The overflow check worked as follows: concatKDF applies the hash function N
times, where N is roundup(kdLen, hashsize) / hashsize. N should not
overflow 32 bits because that would lead to a repetition in the KDF output.

A couple issues with the overflow check:

- It used the hash.BlockSize, which is wrong because the
  block size is about the input of the hash function. Luckily, all standard
  hash functions have a block size that's greater than the output size, so
  concatKDF didn't crash, it just generated too much key material.
- The check used big.Int to compare against 2^32-1.
- The calculation could still overflow before reaching the check.

The new code in concatKDF doesn't check for overflow. Instead, there is a
new check on ECIESParams which ensures that params.KeyLen is < 512. This
removes any possibility of overflow.

There are a couple of miscellaneous improvements bundled in with this
change:

- The key buffer is pre-allocated instead of appending the hash output
  to an initially empty slice.
- The code that uses concatKDF to derive keys is now shared between Encrypt
  and Decrypt.
- There was a redundant invocation of IsOnCurve in Decrypt. This is now removed
  because elliptic.Unmarshal already checks whether the input is a valid curve
  point since Go 1.5.

Co-authored-by: Felix Lange <fjl@twurst.com>

* rpc: metrics for JSON-RPC method calls (#20847)

This adds a couple of metrics for tracking the timing
and frequency of method calls:

- rpc/requests gauge counts all requests
- rpc/success gauge counts requests which return err == nil
- rpc/failure gauge counts requests which return err != nil
- rpc/duration/all timer tracks timing of all requests
- rpc/duration/<method>/<success/failure> tracks per-method timing

* mobile: use bind.NewKeyedTransactor instead of duplicating (#20888)

It's better to reuse the existing code to create a keyed transactor
than to rewrite the logic again.

* internal/ethapi: add CallArgs.ToMessage method (#20854)

ToMessage is used to convert between ethapi.CallArgs and types.Message.
It reduces the length of the DoCall method by about half by abstracting out
the conversion between the CallArgs and the Message. This should improve the
code's maintainability and reusability.

* eth, les: fix flaky tests (#20897)

* les: fix flaky test

* eth: fix flaky test

* cmd/geth: enable metrics for geth import command (#20738)

* cmd/geth: enable metrics for geth import command

* cmd/geth: enable metrics-flags for import command

* core/vm: use a callcontext struct (#20761)

* core/vm: use a callcontext struct

* core/vm: fix tests

* core/vm/runtime: benchmark

* core/vm: make intpool push inlineable, unexpose callcontext

* docs/audits: add discv5 protocol audits from LA and C53 (#20898)

* .github: change gitter reference to discord link in issue template (#20896)

* couple of fixes to docs in clef (#20900)

* p2p/discover: add initial discovery v5 implementation (#20750)This adds an implementation of the current discovery v5 spec.There is full integration with cmd/devp2p and enode.Iterator in thisversion. In theory we could enable the new protocol as a replacement ofdiscovery v4 at any time. In practice, there will likely be a few morechanges to the spec and implementation before this can happen.

* build: upgrade to golangci-lint 1.24.0 (#20901)

* accounts/scwallet: remove unnecessary uses of fmt.Sprintf

* cmd/puppeth: remove unnecessary uses of fmt.Sprintf

* p2p/discv5: remove unnecessary use of fmt.Sprintf

* whisper/mailserver: remove unnecessary uses of fmt.Sprintf

* core: goimports -w tx_pool_test.go

* eth/downloader: goimports -w downloader_test.go

* build: upgrade to golangci-lint 1.24.0

* accounts/abi/bind: Refactored topics  (#20851)

* accounts/abi/bind: refactored topics

* accounts/abi/bind: use store function to remove code duplication

* accounts/abi/bind: removed unused type defs

* accounts/abi/bind: error on tuples in topics

* Cosmetic changes to restart travis build

Co-authored-by: Guillaume Ballet <gballet@gmail.com>

* node: allow websocket and HTTP on the same port (#20810)

This change makes it possible to run geth with JSON-RPC over HTTP and
WebSocket on the same TCP port. The default port for WebSocket
is still 8546.

    geth --rpc --rpcport 8545 --ws --wsport 8545

This also removes a lot of deprecated API surface from package rpc.
The rpc package is now purely about serving JSON-RPC and no longer
provides a way to start an HTTP server.

* crypto: improve error messages in LoadECDSA (#20718)

This improves error messages when the file is too short or too long.
Also rewrite the test for SaveECDSA because LoadECDSA has its own
test now.

Co-authored-by: Felix Lange <fjl@twurst.com>

* changed date of rpcstack.go since new file (#20904)

* accounts/abi/bind: fixed erroneous filtering of negative ints (#20865)

* accounts/abi/bind: fixed erroneous packing of negative ints

* accounts/abi/bind: added test cases for negative ints in topics

* accounts/abi/bind: fixed genIntType for go 1.12

* accounts/abi: minor  nitpick

* cmd: deprecate --testnet, use named networks instead (#20852)

* cmd/utils: make goerli the default testnet

* cmd/geth: explicitly rename testnet to ropsten

* core: explicitly rename testnet to ropsten

* params: explicitly rename testnet to ropsten

* cmd: explicitly rename testnet to ropsten

* miner: explicitly rename testnet to ropsten

* mobile: allow for returning the goerli spec

* tests: explicitly rename testnet to ropsten

* docs: update readme to reflect changes to the default testnet

* mobile: allow for configuring goerli and rinkeby nodes

* cmd/geth: revert --testnet back to ropsten and mark as legacy

* cmd/util: mark --testnet flag as deprecated

* docs: update readme to properly reflect the 3 testnets

* cmd/utils: add an explicit deprecation warning on startup

* cmd/utils: swap goerli and ropsten in usage

* cmd/geth: swap goerli and ropsten in usage

* cmd/geth: if running a known preset, log it for convenience

* docs: improve readme on usage of ropsten's testnet datadir

* cmd/utils: check if legacy `testnet` datadir exists for ropsten

* cmd/geth: check for legacy testnet path in console command

* cmd/geth: use switch statement for complex conditions in main

* cmd/geth: move known preset log statement to the very top

* cmd/utils: create new ropsten configurations in the ropsten datadir

* cmd/utils: makedatadir should check for existing testnet dir

* cmd/geth: add legacy testnet flag to the copy db command

* cmd/geth: add legacy testnet flag to the inspect command

* les, les/lespay/client: add service value statistics and API (#20837)

This PR adds service value measurement statistics to the light client. It
also adds a private API that makes these statistics accessible. A follow-up
PR will add the new server pool which uses these statistics to select
servers with good performance.

This document describes the function of the new components:
https://gist.github.com/zsfelfoldi/3c7ace895234b7b345ab4f71dab102d4



Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
Co-authored-by: rjl493456442 <garyrong0905@gmail.com>

* README: update min go version to 1.13 (#20911)

* travis, appveyor, build, Dockerfile: bump Go to 1.14.2 (#20913)

* travis, appveyor, build, Dockerfile: bump Go to 1.14.2

* travis, appveyor: force GO111MODULE=on for every build

* core/rawdb: fix data race between Retrieve and Close (#20919)

* core/rawdb: fixed data race between retrieve and close

closes https://github.com/ethereum/go-ethereum/issues/20420



* core/rawdb: use non-atomic load while holding mutex

* all: simplify and fix database iteration with prefix/start (#20808)

* core/state/snapshot: start fixing disk iterator seek

* ethdb, rawdb, leveldb, memorydb: implement iterators with prefix and start

* les, core/state/snapshot: iterator fixes

* all: remove two iterator methods

* all: rename Iteratee.NewIteratorWith -> NewIterator

* ethdb: fix review concerns

* params: update CHTs for the 1.9.13 release

* params: release Geth v1.9.13

* added some missing files

* post-rebase fixups

Co-authored-by: Péter Szilágyi <peterke@gmail.com>
Co-authored-by: Martin Holst Swende <martin@swende.se>
Co-authored-by: gary rong <garyrong0905@gmail.com>
Co-authored-by: Alex Willmer <alex@moreati.org.uk>
Co-authored-by: meowsbits <45600330+meowsbits@users.noreply.github.com>
Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: rene <41963722+renaynay@users.noreply.github.com>
Co-authored-by: Ha ĐANG <dvietha@gmail.com>
Co-authored-by: Hanjiang Yu <42531996+de1acr0ix@users.noreply.github.com>
Co-authored-by: ligi <ligi@ligi.de>
Co-authored-by: Wenbiao Zheng <delweng@gmail.com>
Co-authored-by: Adam Schmideg <adamschmideg@users.noreply.github.com>
Co-authored-by: Jeff Wentworth <jeff@curvegrid.com>
Co-authored-by: Paweł Bylica <chfast@gmail.com>
Co-authored-by: ucwong <ucwong@126.com>
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Luke Champine <luke.champine@gmail.com>
Co-authored-by: Boqin Qin <Bobbqqin@gmail.com>
Co-authored-by: William Morriss <wjmelements@gmail.com>
Co-authored-by: Guillaume Ballet <gballet@gmail.com>
Co-authored-by: Raw Pong Ghmoa <58883403+q9f@users.noreply.github.com>
Co-authored-by: Felföldi Zsolt <zsfelfoldi@gmail.com>

This is supposed to fix the occasional failures in 
TestCancel* on Travis CI.

This removes the error added in #20597 in favor of a log message at
error level. Failing to start broke a bunch of people's setups and is
probably not the right thing to do for this check.

This fixes a bunch of cases where a timeout in the test would leak
a goroutine.

Fixes #20467

Co-authored-by: meowsbits <45600330+meowsbits@users.noreply.github.com>

This change makes the client attempt to reconnect when a write fails.
We already had reconnect support, but the reconnect would previously
happen on the next call after an error. Being more eager leads to a
smoother experience overall.

This commit intents to replicate the DialHTTPWithClient function which allows
creating a RPC Client using a custom dialer but for websockets.

We introduce a new DialWebsocketWithDialer function which allows the caller
to instantiate a new websocket client using a custom dialer.

* initial commit

* add callers

* restore mining for retesteth

* unlock even if panics

* try to restore accountRange

* fmt

* rename MineBlock

* fmt

* linters

* rpc: remove 'exported or builtin' restriction for parameters

There is no technial reason for this restriction because package reflect
can create values of any type. Requiring parameters and return values to
be exported causes a lot of noise in package exports.

* rpc: fix staticcheck warnings

* rpc: improve codec abstraction

rpc.ServerCodec is an opaque interface. There was only one way to get a
codec using existing APIs: rpc.NewJSONCodec. This change exports
newCodec (as NewFuncCodec) and NewJSONCodec (as NewCodec). It also makes
all codec methods non-public to avoid showing internals in godoc.

While here, remove codec options in tests because they are not
supported anymore.

* p2p/simulations: use github.com/gorilla/websocket

This package was the last remaining user of golang.org/x/net/websocket.
Migrating to the new library wasn't straightforward because it is no
longer possible to treat WebSocket connections as a net.Conn.

* vendor: delete golang.org/x/net/websocket

* rpc: fix godoc comments and run gofmt

This change adds support for EIP-1898. 

This change adds support for gzip encoding on HTTP responses.
Gzip encoding is used when the client sets the 'accept-encoding: gzip' header.
Original change by @brianosaurus, with fixes from @SjonHortensius.

* rpc: implement websockets with github.com/gorilla/websocket

This change makes package rpc use the github.com/gorilla/websocket
package for WebSockets instead of golang.org/x/net/websocket. The new
library is more robust and supports all WebSocket features including
continuation frames.

There are new tests for two issues with the previously-used library:

  - TestWebsocketClientPing checks handling of Ping frames.
  - TestWebsocketLargeCall checks whether the request size limit is
    applied correctly.

* rpc: raise HTTP/WebSocket request size limit to 5MB

* rpc: remove default origin for client connections

The client used to put the local hostname into the Origin header because
the server wanted an origin to accept the connection, but that's silly:
Origin is for browsers/websites. The nobody would whitelist a particular
hostname.

Now that the server doesn't need Origin anymore, don't bother setting
one for clients. Users who need an origin can use DialWebsocket to
create a client with arbitrary origin if needed.

* vendor: put golang.org/x/net/websocket back

* rpc: don't set Origin header for empty (default) origin

* rpc: add HTTP status code to handshake error

This makes it easier to debug failing connections.

* ethstats: use github.com/gorilla/websocket

* rpc: fix lint

This PR updates a comment about the maximum client subscription buffer
to reflect changes made previously, and fixes a test that wouldn't fail
when wantError == true but execution did not return an error.

When cancelling the context for a call on a HTTP-based client while the
call is running, the select in requestOp.wait may hit the <-context.Done()
case instead of the <-op.resp case. This doesn't happen often -- our
cancel test hasn't caught this even though it ran thousands of times
on CI since the RPC client was added.

Fixes #19714

* p2p: remove direct import of cgo-library

* accounts, rpc: more nocgo alternatives

* rpc: move unix path constant into separate file

* accounts/scwallet: address review concerns, remove copy-pasta

This corrects the previous change which broke the build and
was pushed by accident.

New APIs added:

    client.RegisterName(namespace, service) // makes service available to server
    client.Notify(ctx, method, args...)     // sends a notification
    ClientFromContext(ctx)                  // to get a client in handler method

This is essentially a rewrite of the server-side code. JSON-RPC
processing code is now the same on both server and client side. Many
minor issues were fixed in the process and there is a new test suite for
JSON-RPC spec compliance (and non-compliance in some cases).

List of behavior changes:

- Method handlers are now called with a per-request context instead of a
  per-connection context. The context is canceled right after the method
  returns.
- Subscription error channels are always closed when the connection
  ends. There is no need to also wait on the Notifier's Closed channel
  to detect whether the subscription has ended.
- Client now omits "params" instead of sending "params": null when there
  are no arguments to a call. The previous behavior was not compliant
  with the spec. The server still accepts "params": null.
- Floating point numbers are allowed as "id". The spec doesn't allow
  them, but we handle request "id" as json.RawMessage and guarantee that
  the same number will be sent back.
- Logging is improved significantly. There is now a message at DEBUG
  level for each RPC call served.

* Initial work on a graphql API

* Added receipts, and more transaction fields.

* Finish receipts, add logs

* Add transactionCount to block

* Add types  and .

* Update Block type to be compatible with ethql

* Rename nonce to transactionCount in Account, to be compatible with ethql

* Update transaction, receipt and log to match ethql

* Add  query operator, for a range of blocks

* Added ommerCount to Block

* Add transactionAt and ommerAt to Block

* Added sendRawTransaction mutation

* Add Call and EstimateGas to graphQL API

* Refactored to use hexutil.Bytes instead of HexBytes

* Replace BigNum with hexutil.Big

* Refactor call and estimateGas to use ethapi struct type

* Replace ethgraphql.Address with common.Address

* Replace ethgraphql.Hash with common.Hash

* Converted most quantities to Long instead of Int

* Add support for logs

* Fix bug in runFilter

* Restructured Transaction to work primarily with headers, so uncle data is reported properly

* Add gasPrice API

* Add protocolVersion API

* Add syncing API

* Moved schema into its own source file

* Move some single use args types into anonymous structs

* Add doc-comments

* Fixed backend fetching to use context

* Added (very) basic tests

* Add documentation to the graphql schema

* Fix reversion for formatting of big numbers

* Correct spelling error

* s/BigInt/Long/

* Update common/types.go

* Fixes in response to review

* Fix lint error

* Updated calls on private functions

* Fix typo in graphql.go

* Rollback ethapi breaking changes for graphql support
Co-Authored-By: Arachnid <arachnid@notdot.net>