Default argument value for options in Discussion so that inline discussions can still

work without modification. Eventually we'll want to switch the pagination there to
match the pagination on the main forum though.

lms/static/coffee/src/discussion/discussion.coffee

@@ -2,7 +2,7 @@ if Backbone?
   class @Discussion extends Backbone.Collection
     model: Thread
 
-    initialize: (models, options)->
+    initialize: (models, options={})->
       @pages = options['pages'] || 1
       @current_page = 1
       @bind "add", (item) =>