added comment to explain sorting

common/static/coffee/src/discussion/discussion.coffee

@@ -62,8 +62,7 @@ if Backbone?
         #The comment client asks each thread for a value by which to sort the collection
         #and calls this sort routine regardless of the order returned from the LMS/comments service
         #so, this takes advantage of this per-thread value and returns tomorrow's date
-        #for pinned threads, ensuring that they appear first, which is the intent of pinned threads
-        #the negative is to display most recent first
+        #for pinned threads, ensuring that they appear first, (which is the intent of pinned threads)
         #
         if thread.get('pinned')
           #use tomorrow's date
@@ -76,7 +75,7 @@ if Backbone?
     sortByDateRecentFirst: (thread) ->
         #
         #Same as above
-        #the negative is to display most recent first (basically to flip the order)
+        #but negative to flip the order (newest first)
         #
         if thread.get('pinned')
           #use tomorrow's date