Note when posts have been updated, and put the creation date in the title text.

lms/djangoapps/django_comment_client/utils.py

@@ -222,6 +222,7 @@ def extend_content(content):
         'raw_tags': ','.join(content.get('tags', [])),
         'permalink': permalink(content),
         'roles': roles,
+        'updated': content['created_at']!=content['updated_at'],
     }
     return merge_dict(content, content_info)
 

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

@@ -374,6 +374,9 @@ if Backbone?
       MathJax.Hub.Queue ["Typeset", MathJax.Hub, $contentBody.attr("id")]
 
     initTimeago: ->
+      @$("span.timeago").each (index, element) ->
+        elem = $(element)
+        elem.html("posted on #{$.timeago.parse(elem.html()).toLocaleString()}")
       @$("span.timeago").timeago()
 
     renderPartial: ->

lms/templates/discussion/mustache/_content.mustache

@@ -29,7 +29,10 @@
         {{/thread}}
         <div class="info">
           <div class="comment-time">
-            <span class="timeago" title="{{content.updated_at}}">sometime</span> by
+            {{#content.updated}}
+              updated
+            {{/content.updated}}
+            <span class="timeago" title="{{content.updated_at}}">{{content.created_at}}</span> by
             {{#content.anonymous}}
               anonymous
             {{/content.anonymous}}