p2p/nat: fix #2291, NAT discovery did't abort on failure

core: added future proc mutex lock

core: cache fresh headers and tds to avoid db trashing

Added a future lock which prevents the anything being added or removed
from or to the set when looping over the set of blocks. This fixes a nil
pointer in the range loop when trying to retrieve a block from the set
which was previously available but removed due to regular chain
processing.

Fixes #2305

Godeps: pull in the leveldb upstream write race fix

eth/downloader: fix a throughput estimation data race

core: create a header chain structure shared by full and light clients

core: announce ChainSideEvent during reorg

Godeps: update goleveldb to fix a compaction data race

cmd, eth, ethdb, node: prioritise chaindata for resources, bump cache

Previously all blocks that were already in our chain were never re
announced as potential uncle block (e.g. ChainSideEvent). This is
problematic during mining where you want to gather as much possible
uncles as possible increasing the profit. This is now addressed in this
PR where during reorganisations of chains the old chain is regarded as
uncles.

Fixed #2298

console: allow optional password on the command line

Godeps: pull in ethash future cache generator

Adds --keystore

Fix path problem with Solidity compile with filepath.Glob on Windows

eth: forward empty body responses to the downlaoder

console: cleanup old autocompletations relics

core, miner: add PendingStateEvent to track non-log updates.

rpc: simplify inproc client

Fixes #2277

crypto: expose key decryption method to parse a string direclty

core: improved check for contract creation

cmd/geth: removed multiline support

cmd/utils: lower the min accepted gas price for relay and GPO