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/opcodes.go

@@ -404,6 +404,7 @@ var stringToOp = map[string]OpCode{
 	"CALLDATALOAD": CALLDATALOAD,
 	"CALLDATASIZE": CALLDATASIZE,
 	"CALLDATACOPY": CALLDATACOPY,
+	"DELEGATECALL": DELEGATECALL,
 	"CODESIZE":     CODESIZE,
 	"CODECOPY":     CODECOPY,
 	"GASPRICE":     GASPRICE,