* 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.
The transaction pool will now some easily be able to pre determine the
validity of a transaction by checking the following:
* Account existst
* gas limit higher than the instrinsic gas
* enough funds to pay upfront costs
* nonce check
Logs are now recorded per transactions instead of tossing them out after
each transaction. This should also fix an issue with
`eth_getFilterLogs` (#629) Also now implemented are the `transactionHash,
blockHash, transactionIndex, logIndex` on logs. Closes#654.
