params: stable version 1.5.5

miner: clean up unconfirmed mined block tracking

cmd/swarm: one command  with subcommands

build: Ubuntu wily was officially deprecated, drop support

core: init pending state in tx pool on creation

cmd/utils, eth: Add gzip support for chain dump and restore

travis, appveyor: build with Go 1.7.4

cmd/geth: drop legacy android code

Miner race fixes

cmd/swarm: subsume cmd/bzz* under cmd/swarm as subcommands

les, p2p/discv5: implement server pool, improve peer selection, light fetcher and topic searching

netstats: time and block history

NSIS has a default MAX_STR_LEN of 1024. If $ENV{PATH} is longer
the returned string is truncated to an empty string. Its then not
possible to distinguis between the variable not set or too long.
As a result the variable is set with the location where geth and/or
dev tools are installed. This may override any previous set values.

The transaction pool keeps track of the current nonce in its local pendingState. When a
new block comes in the pendingState is reset. During the reset it fetches multiple times
the current state through the use of the currentState callback. When a second block comes
in during the reset its possible that the state changes during the reset. If that block
holds transactions that are currently in the pool the local pendingState that is used to
determine nonces can get out of sync.