[Twisted-Python] jelly with new-style classes: method references are not resolved

Hi, while trying to port jelly to Python 3 (banana tests already pass with Python 3), I found a bug in jelly. It has already been reported 3 years ago with ticket 4935. And there is a fix attached to that ticket. This fix resolves the problem for me. Why has this fix never been included? It is necessary for porting to Python 3. -- Wolfgang