-typedef void(*user_callback)( Messenger& mr, Message& m, int mtype, int subid, int payload_len, Msg_component payload, void* usr_data );
- //std::unique_ptr<unsigned char,unfreeable> payload, void* usr_data );
+typedef void(*user_callback)( Message& m, int mtype, int subid, int payload_len, Msg_component payload, void* usr_data );