Gajim hangs when it loses connection
When I lose internet connection and thus I get disconnected from my Jabber server, Gajim hangs, making me unable to see what was written in a conversation window, I can't see the roster if I don't wait some (long) time.
We now optionnaly use python-libasyncns when it's available. (it's buggy, but I already informed developper). see #4843)