Known bugs:
- There is a problem with alternate nick and nick changing in MUC which
  seems to appears when the connection is lost and the client automatically
  reconnects. (bug spotted by davux)

Next release(s):
- Write the documentation in help/ for the commmands:
    ROSTER, PRESENCE, XMPPREGISTER, XMPPUNREGISTER, XMPPPASSWD
- Handle errors and print errors messages (many errors are not handled
  yet, specially in MUC)
- Rewrite completion (src/fe-common/xmpp-completion.c)
- Add the commands /KICK and /BAN in MUCs
- Implement the commands /SERVICES DISCOVER/LOGON/LOGOFF to
  print info/activate/deactivate a service (like a gateway)
        <presence to="<<service>>" id="1"></presence>
	<presence to="<<service>>" type="unavailable" id="2"></presence>

Delayed tasks:
- Print name instead of jid in queries messages:
    One way to do it is to create new signals (like "message xmpp private"
instead of "message private") and handle these new signals to print the
nickname. The major problem is that you have to stop the signal "message
private" to replace it with "message xmpp private", but many things in
irssi handle the original signal so you have to recreate the same
behaviors inside irssi-xmpp (which is complicated and boring). For
inspiration you can see how the signal "message own_public" is handled
in src/fe-common/fe-xmpp-messages.c
    The other (and better) way to do it, is to modify some signal emitted
by irssi (at least "message private", to add a new parameter which will
be the nick to display) and to modify the way irssi handle these new
signals.
