cmd, core, miner: add --txpool.locals and priority mining

* cmd, eth, miner: make recommit configurable

* cmd, eth, les, miner: polish a bit

* miner: filter duplicate sealing work

* cmd: remove uncessary conversion

* miner: avoid microptimization in favor of cleaner code

consensus/clique, light: light client snapshots on Rinkeby

* swarm, swarm/network, swarm/pss: log error and fix logs

* swarm/pss: log compressed publickey

crypto/bn256: add missing license file, release wrapper in BSD-3

Ensure from < to when tracing chain

* cmd/puppeth: Accept identityfile in the server string with fallback to id_rsa

* cmd/puppeth: code polishes + fix heath check double ports

console: fixed comment typo

consensus/ethash: reduce notify test aggressiveness

miner: update mining log with correct fee calculation

* les: fix crasher in NodeInfo when running as server

The ProtocolManager computes CHT and Bloom trie roots by asking the
indexers for their current head. It tried to get the indexers from
LesOdr, but no LesOdr instance is created in server mode.

Attempt to fix this by moving the indexers, protocol creation and
NodeInfo to a new lesCommons struct which is embedded into both server
and client.

All this setup code should really be cleaned up, but this is just a
hotfix so we have to do that some other time.

* les: fix commons protocol maker

crypto/bn256: fix issues caused by Go 1.11

consensus/ethash: use DAGs for remote mining, generate async

miner: add gas and fee details to mining logs