* core: reinit chain from freezer in batches

* core/rawdb: concurrent database reinit from freezer dump

* core/rawdb: reinit from freezer in sequential order

Without this, accounts/keystore fails to build for Darwin with
CGO_ENABLED=0.

core/rawdb: keep genesis in key-value store for full sync too

* eth, les: reject light client connection is server is not synced

* eth, les: rename function and variables

* les: format

* 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

* Added checks for nil pointers in Marshal functions

* Set nil pointer to identity in GT before marshaling

* tests: make transaction tests run again, fix #19033

* tests: refactor transaction tests

* log: Do not pad too long values

* log: gofmt

* les: avoid fetcher deadlock on requestChn

core/rawdb, eth/downloader: align 64bit atomic fields

* build: disable swarm packages

* build: remove allCrossCompiledArchiveFiles; inline allToolsArchiveFiles

* build: get rid of some superfluous comments

cmd, core, eth, les, node: chain freezer on top of db rework

* swarm/network: bump network id for 0.4 release

* swarm/network: bump bzz protocol version

* swarm/docs: migration document v0.3 to v0.4

* swarm/storage/feed: gofmt lookup_test.go

* core, eth: some fixes for freezer

* vendor, core/rawdb, cmd/geth: add db inspector

* core, cmd/utils: check ancient store path forceily

* cmd/geth, common, core/rawdb: a few fixes

* cmd/geth: support windows file rename and fix rename error

* core: support ancient plugin

* core, cmd: streaming file copy

* cmd, consensus, core, tests: keep genesis in leveldb

* core: write txlookup during ancient init

* core: bump database version

* freezer: disable compression on hashes and difficulties

* core/rawdb: address review concerns

* core/rawdb: address review concerns

* all: freezer style syncing

core, eth, les, light: clean up freezer relative APIs

core, eth, les, trie, ethdb, light: clean a bit

core, eth, les, light: add unit tests

core, light: rewrite setHead function

core, eth: fix downloader unit tests

core: add receipt chain insertion test

core: use constant instead of hardcoding table name

core: fix rollback

core: fix setHead

core/rawdb: remove canonical block first and then iterate side chain

core/rawdb, ethdb: add hasAncient interface

eth/downloader: calculate ancient limit via cht first

core, eth, ethdb: lots of fixes

* eth/downloader: print ancient disable log only for fast sync

* freezer: implement split files for data

* freezer: add tests

* freezer: close old head-file when opening next

* freezer: fix truncation

* freezer: more testing around close/open

* rawdb/freezer: address review concerns

* freezer: fix minor review concerns

* freezer: fix remaining concerns + testcases around truncation

* freezer: docs

* freezer: implement multithreading

* core/rawdb: fix freezer nitpicks + change offsets to uint32

* freezer: preopen files, simplify lock constructs

* freezer: delete files during truncation

This change implements EIP-868. The UDPv4 transport announces support
for the extension in ping/pong and handles enrRequest messages.

There are two uses of the extension: If a remote node announces support
for EIP-868 in their pong, node revalidation pulls the node's record.
The Resolve method requests the record unconditionally.

These changes fix two corner cases related to internal handling of types
in package rlp: The "tail" struct tag can only be applied to the last field.
The check for this was wrong and didn't allow for private fields after the
field with the tag. Unsupported types (e.g. structs containing int) which
implement either the Encoder or Decoder interface but not both 
couldn't be encoded/decoded.

Also fixes #19367