trie: approximate the wasted cache metaspace closer

eth, les, light: enforce CHT checkpoints on fast-sync too

appveyor.yml: Upgraded to Go 1.12.4

core, eth, les, light: avoid storing computable receipt metadata 

swarm/storage/feed: add context handling/cancellation to Swarm Feeds lookup, fix bad hint lookup bug (#19353)

* swarm/storage/feed/lookup: Add context handling/forwarding

* swarm/storage/feed/lookup: Add test to catch bad hint

* swarm/storage/feed/lookup: Added context cancellation test

 This makes geth fails instead of falling back to local keystore, if the command line flag `--signer` is used

* cmd/clef, signer: make fourbytes its own package, break dep cycle

* signer/fourbyte: pull in a sanitized 4byte database

* swarm/api: fix file descriptor leak in NewTestSwarmServer

Swarm storage (localstore) was not closed. That resulted a
"too many open files" error if `TestClientUploadDownloadRawEncrypted`
was run with `-count 1000`.

* cmd/swarm: speed up StartNewNodes() by parallelization

Reduce cluster startup time from 13s to 7s.

* swarm/api: disable flaky TestClientUploadDownloadRawEncrypted with -race

* swarm/storage: disable flaky TestLDBStoreCollectGarbage (-race)

With race detection turned on the disabled cases often fail with:
"ldbstore_test.go:535: expected surplus chunk 150 to be missing, but got no error"

* cmd/swarm: fix process leak in TestACT and TestSwarmUp

Each test run we start 3 nodes, but we did not terminate them. So
those 3 nodes continued eating up 1.2GB (3.4GB with -race) after test
completion.

6b6c4d1c changed how we start clusters
to speed up tests. The changeset merged together test cases
and introduced a global cluster. But "forgot" about termination.

Let's get rid of "global cluster" so we have a clear owner of
termination (some time sacrifice), while leaving subtests to use the
same cluster.

* clef: bundle 4byte db into clef, fix #19048

* clef: add go-generate directive, remove internal abidb parser tool

* cmd/clef: extend go generate to format asset file

* metrics/prometheus: added prometheus http server and metrics collector

* metrics/prometheus: minor cleanups

* metrics/prometheus: named keys instead name in tag

* metrics/prometheus: minor typo cleanups, sorted report

* clef: update warning-text

* Update cmd/clef/main.go

Update the app download link to the latest version, as requested in #19418

vendor: fix some vendor config leftover

* vendor: remove leftover trace

* Upgrade go-libpcsclite to the latest version

appveyor.yml: Upgraded to Go 1.12.3

* accounts, core, internal, node: Add support for smartcard wallets

* accounts, internal: Changes in response to review

* vendor: pull in missing go-echd library

* accounts/scwallet, console: user friendly card opening

* accounts/scwallet: ordered wallets, tighter events, derivation logs

* accounts, console: frendly card errors, support pin unblock

* accounts/scwallet: fix crypto API change

* accounts/scwallet: rebase and update

* Fix some linter issues

* Remove the direct dependency on libpcsclite

Instead, use a go library that communicates with pcscd over a socket.

Also update the changes introduced by @gravityblast since this PR's
inception

* Temporary fix to the ADBU status call

* fix wallet status update

This is a temporary fix, better checks need to
be performed once the whole process has been
validated.

* Fix key derivation

* Add some documentation

* Update a comment to reflect the workings of the updated system

* Vendor keycard-go/derivationpath

* Formatting fixes

* Add instructions on how to install the card

* Achieve full transaction signature+sending

* PK derivation has to be supported by the card

* Fix linter issues

* Upgrade to keycard app v2.1.1

* Set gballet as codeowner of the smartcard wallet dir

* fix unnecessary condition linter warning

* refuse to overwrite the master key of a previously initialized card

* refresh the account list when initializing the card

* Update the card preparation instructions based on review feedback

* 'sanitize' JSON input

Co-Authored-By: gballet <gballet@gmail.com>

* Apply suggestions from code review

Co-Authored-By: gballet <gballet@gmail.com>

* fix a serialization error

* more review feedback

* More review feedback

* Can now specify the number of empty accounts to derive

* Fix rebase error: include norm package

* Update bip-39 ref and remove ebfe/scard from vendor

* Add missing dependency

This PR fixes this, moving domain.ChainId from the map's initializer down to a separate if statement which checks the existance of ChainId's value, similar to the rest of the fields, before adding it. I've also included a new test to demonstrate the issue

les: remove support for LES/1