* PREVHASH => BLOCKHASH( N )
* State transition object uses VMEnv as it's query interface
* Updated vm.Enviroment has GetHash( n ) for BLOCKHASH instruction
* Added GetHash to xeth, core, utils & test environments

* Stack Error shouldn't revert to previous state
* Updated VM Test tool
* Added Transfer method to VM Env

Standard VM should be about 10x faster than the debug VM. Some error
checking has been removed, all of the log statements and therefor quite
some unnecessary if-statements.

* EXT- CODECOPY, CODESIZE

* The State and StateObject have been moved to their own package
* The VM is moved to it's own package