core, core/vm, crypto: fixes for homestead

* Removed some strange code that didn't apply state reverting properly
* Refactored code setting from vm & state transition to the executioner
* Updated tests

core/vm/environment.go

@@ -121,7 +121,6 @@ type Account interface {
 	SetNonce(uint64)
 	Balance() *big.Int
 	Address() common.Address
-	SetAddress(common.Address)
 	ReturnGas(*big.Int, *big.Int)
 	SetCode([]byte)
 	EachStorage(cb func(key, value []byte))