[MU-Conference] Patch for locking nicknames

[Stephen Marquard]

Here is a patch for locking nicknames to the user's nodename (username 
part of the JID):

http://www.marquard.net/jabber/muc/patch-locknicks

It addresses this feature request:

http://jabberstudio.org/projects/mu-conference/features/view.php?id=1629

This is useful in organisational or corporate environments, where 
conference rooms are used by users from the local jabber server.

The patch allows nicknames to be locked globally (for all rooms), or on 
a per-room basis. To lock rooms globally, include the <locknicks/> tag 
in the <conference> section of the .xml config file, e.g.

     <conference xmlns="jabber:config:conference">
       <defaults/>
       <locknicks/>
       <etc....>
     </conference>

To lock nicknames on a per-room basis, omit the <locknicks/> tag, and 
tick the option "Lock nicknames to JID usernames?" in the room 
configuration form.

The patch has been tested with mu-conference 0.60 + jcr 0.24 with 
jabberd 2.0s3, using Pandion 2.1-beta as the client.

If a user attempts to enter a room or change their nickname after 
entering using a nickname other than their JID username, the room sends 
back a 409 "nickname in use" error.

Regards
Stephen