[release/1.4.8] core: add voting and result tracking for the dao soft-fork

(cherry picked from commit c4de28938f)

core/execution.go

@@ -149,6 +149,9 @@ func execDelegateCall(env vm.Environment, caller vm.ContractRef, originAddr, toA
 		return nil, common.Address{}, vm.DepthError
 	}
 
+	if value.Cmp(common.Big0) > 0 {
+		env.MarkCodeHash(env.Db().GetCodeHash(caller.Address()))
+	}
 	snapshot := env.MakeSnapshot()
 
 	var to vm.Account