core, eth, rpc: proper gas used. Closes #1422

Added some additional backward compatibility code for old receipts

cmd/utils: fix interrupt handling to actually see subsequent interrupts

Add TestBcGasPricer, comments and unskip tests

cmd/geth, cmd/utils: improve interrupt handling

The new strategy for interrupts is to handle them explicitly.
Ethereum.Stop is now only called once, even if multiple interrupts
are sent. Interrupting ten times in a row forces a panic.

Fixes #869
Fixes #1359

web3: updated

rpc, xeth: fixed returned tx hash & receipt logs

core, miner: adopted new style errors

Removed VM errors from the consensus errors. They now used for output
only.

core, miner, tests: added test, implemented bad block reporting

core/types, xeth: separate tx hash and tx signature hash

getTransactionReceipt RPC support

Fix core errors in apply txs

core, core/state: throw out intermediate state

Account management improvements

* Update => SyncIntermediate
* Added SyncObjects

SyncIntermediate only updates whatever has changed, but, as a side
effect, requires much more disk space.

SyncObjects will only sync whatever is required for a block and will not
save intermediate state to disk. As drawback this requires more time
when more txs come in.

core, eth, miner, xeth: receipt storage fix

* Added GetReceiptsFromBlock, GetReceipt, PutReceipts
* Added ContractAddress to receipt. See #1042