[Twisted-Python] Issue with factories

[Itamar Shtull-Trauring]

Itamar Shtull-Trauring wrote:

 > If you do reactor.listenTCP on a factory, startFactory and stopFactory are
 > never called. I therefore suggest that we add methods doStart and doStop
 > to protocol.Factory, like so, and have them called in listenTCP/UDP/SSL,
 > and remove calls to start/stopFactory from app.Appliecation:

OK, done, basically identically to the pseudocode listed in previous email,
slighly improved - I will check in after 0.18 is released.