Added the ability to submit byte code for contracts instead of Mutan code.

ethutil/bytes.go

@@ -83,3 +83,8 @@ func CopyBytes(b []byte) (copiedBytes []byte) {
 
 	return
 }
+
+func IsHex(str string) bool {
+	l := len(str)
+	return l >= 4 && l%2 == 0 && str[0:2] == "0x"
+}