core: add status as a consensus field in receipt

* cmd/evm, core/vm, internal/ethapi: Add 'err' to tracer interface CaptureEnd

* cmd/evm: fix nullpointer when there is no error

node: fix instance dir locking and improve error message

metrics: change MetricsEnabledFlag to be const

tests: enable Byzantium state tests for CI

Signed-off-by: Ti Zhou <tizhou1986@gmail.com>

vendor: update USB HID lib (fix macOS crash)

core/vm: implement REVERT metropolis opcode

* whisper: Fix spelling and grammar in error

* whisper: Fix grammar in comments

README: add missing full stop

missing period at line 119

The lock file was ineffective because opening leveldb storage in
read-only mode doesn't really take the lock. Fix it by including a
dedicated flock library (which is actually split out of goleveldb).

eth: send but not announce block to peers if propagate is true

cmd/puppeth: support blacklisting malicious IPs on ethstats

core/vm, crypto/bn256: fix bn256 use and pairing corner case

core/vm: implement RETURNDATA metropolis opcodes

core/vm: implement metropolis static call opcode

 * Fix STATICCALL so it is able to call precompiles too
 * Fix write detection to use the correct value argument of CALL
 * Fix write protection to ignore the value in CALLCODE

core/vm: metropolis precompiles

swarm: fix megacheck warnings