Pass through all commands to RPC

That is what it does, excepting `create`, as that one also does transacting, it replaces `query`(maybe nicer naming than `storageAt`) and `transact`. I didnt make a file/class in `lib/epm/`, not sure if i should. Why? suppose it separates concerns a bit, i could do it simular.

All the commands are equivalent to the RPC ones, you can specify arguments in order or by keywords,(last overriding) and some defaults are in there, and it is flexible in how those defaults are made.

A disadvantage is that `epm help` now lists an awful lot of commands.. Maybe i should change that to `epm rpc ....`, and put `epm query` back.

Tested it on a contract, seems to work, except `isContract` for some reason... (nearly got to be a cpp-ethereum bug, nothing specific to it here)