datetime.strftime seems (according to cProfile) to be VERY slow. Improve the refresh performances by reducing A LOT the number of call of this method

/list command, can join the room with J (cannot sort, search or filter yet, and lacks some information)

completion of the jid's node when doing /join ro@some.server.fr/[TAB](it completes the 'ro' part \o/. Also a begining of /list command, but that does nothing

command completion. Also completion for command's arguments. (try it to complete the server of the muc with /join test@kiko[TAB]  for example