* Refactor and port CLI from Docopt to Clap (#2066)
* Add --can-restart and --force-direct to help
* Add flag support to subc & move import/export options to subcommand
* Reorder subcommand args (put positional args last in CLI help message)
* The front-end for each hard-fork, also EIP-160.
* Address EIP161 a/c
* Include EIP-161b
* EIP-161 part d.
* Fix test build.
* Fix one test, add another.
* Fix use of bloom & renaming.
* Initial groundwork for EIP-155
* Fix minor bug.
* Fix all tests finally.
* Rest of EIP-155.
* Add tests for EIP-155 algorithm.
Update transaction tests validation.
* Minor reformat.
* Address grumbles.
* Remove unused code.
* Fix SUICIDE gas mechanism and add consensus tests.
* Remove commented code.
* Set Frontier hardfork block number
* Fix warning.
* Transaction tests,
