Fix panic when downloading stales, update homestead transition

changing x64 asm config

uncomment state transition tests

jsonrpc uses weak pointers to client

Morden switch to Homestead rules at #494,000.

Blockchain module cleanup

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