======Synopsis:======
[[on]] channel_nick

======Summary:======
Triggered by other people's [[nick]] changes.

======Description:======
This event is thrown each time someone (including you) on one of
your channels changes nickname.  If the nick changer is on multiple channels
with you, multiple events are thrown.  

======Parameters:======
|$0   | The channel of the nick changer |
|$1   | The nick changer's old nickname |
|$2   | The nick changer's new nickname |

======Default Action:======
If you don't suppress this event, the client will throw an [[on nickname]] 
event.

======Examples:======
To make a distinction between the client changing nicks and other people:
   on ^channel_nick '% $servernick() *' (chan, oldnick, newnick) {
      xecho -b You have changed nicks to $newnick;
   };
   on ^channel_nick * (chan, oldnick, newnick) {
      if (iscurchan($chan)) {
         xecho -b $oldnick has changed nicks to $newnick;
      } else {
         xecho -b $oldnick has changed nicks to $newnick on $chan;
      };
   };

======History======
This already existed in ircII.