[typo] jabber notifications

[Alex Deva]

First problem: it didn't work at all until I manually installed  
xmpp4r. Shouldn't this come with the installation?

Second problem: in the Comment model (app/models/comment.rb), in the  
'notify_user_via_jabber' method, there's a reference to  
'controller.url_for'. Rails doesn't know who "controller" is. I  
removed the reference, and now Jabber notifications work (although  
without including the link to the article in question).

Anyone know the correct way of finding the url for an article from  
within the Comment (or any other) model?