* change gas cost for contract creating txs
* invalidate signature with s value greater than secp256k1 N / 2
* OOG contract creation if not enough gas to store code
* new difficulty adjustment algorithm
* new DELEGATECALL op code
Conflicts:
core/vm/environment.go
crypto/crypto.go
crypto/secp256k1/secp256.go
eth/api.go
The runtime environment can be used for simple basic execution of
contract code without the requirement of setting up a full stack and
operates fully in memory.