Nonce fix for failing transactions

Parallelise nonce checks

Add "removedb" command to Geth

Removes the state and blockchain databases

Multiple CORS domains support

Separated by spaces

fixed race condition in miner

ChainManager now uses a parallel approach to block processing where all
nonces are checked seperatly from the block processing process. This
speeds up the process by about 3 times on my i7

core: global chain insert lock

cmd/geth: delete state db on upgradedb command

Start event has moved because it could possibly could stall the miner

core, miner: fork resolving and restart miner after sync op