Multiplication issue + very exhaustive tests for it

EIP-8

Conflicts:
	util/src/uint.rs

Make "random" trie tests fully deterministic.

udpated serde to version 0.7.0

Better memory management

Typo

U512 add/sub optimize

Account management + geth keystore import (no utility crate added)

Delayed UPnP initialization

Fixing marking blocks as bad & SyncMessage bugs + small client refactoring.

Conflicts:
	ethcore/src/client.rs

optimization of U256

Removed rocksdb from build scripts and instructions