* add-date-to unstable
* fields-insteadof-split
* internal/build: support building with missing git
* docker: add git history back to support commit date in version
* internal/build: use PR commits hashes for PR builds
* build: add support for different package and binary names
* build: bump up copyright date
* build: change default PackageName to empty string
* build, internal, swarm: enhance build/release process
* build: hack ethereum-swarm as a "depends" in deb package
* build/ci: remove redundant variables
* build, cmd, mobile, params, swarm: remove VERSION file; rename Version to VersionMeta;
* internal: remove VERSION() method which reads VERSION file
* build: fix VersionFilePath to Version
* Makefile: remove clean_go_build_cache.sh until it works
* Makefile: revert removal of clean_go_build_cache.sh
This commit adds pluggable consensus engines to go-ethereum. In short, it
introduces a generic consensus interface, and refactors the entire codebase to
use this interface.
