RPC cleanup

Fix key store address hex decoding and accounts test

Thanks to https://github.com/jaekwon for original fix!

Convert gas values to integers

Implement OS sensitive dataDirs

Allow zero and negative block numbers

topics fix

Fixes #370

* Added an additional tx state which is used to get the current nonce
* Refresh transient state each time a new canonical block is found
* Properly uninstall filters. Fixes a possible crash in RPC

0 is genesis block. Xeth recognises -1 as current

Correct stack size validation for MUL, CALLDATACOPY, EXTCODESIZE, BLOCKH...

Persistent Node Key

* Implemented `eth_logs`
* Fixed issue with `filter.Find()` where logs were appended to an
  incorrect, non-returned slice resulting in no logs found

Don't print per-function testing results