Remove /forum/ from discussion URLs because discussion/forum/ is redundant.

lms/djangoapps/django_comment_client/urls.py

 from django.conf.urls.defaults import url, patterns, include
 
 urlpatterns = patterns('',
-    url(r'forum/?', include('django_comment_client.forum.urls')),
     url(r'', include('django_comment_client.base.urls')),
+    url(r'', include('django_comment_client.forum.urls')),
 )

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

@@ -13,7 +13,7 @@ if Backbone?
       Content.loadContentInfos(content_info)
       discussion = new Discussion(threads, pages: thread_pages)
       new DiscussionRouter({discussion: discussion})
-      Backbone.history.start({pushState: true, root: "/courses/#{$$course_id}/discussion/forum/"})
+      Backbone.history.start({pushState: true, root: "/courses/#{$$course_id}/discussion/"})
   DiscussionProfileApp =
     start: (elem) ->
       element = $(elem)

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

@@ -57,17 +57,17 @@ class @DiscussionUtil
       downvote_comment        : "/courses/#{$$course_id}/discussion/comments/#{param}/downvote"
       undo_vote_for_comment   : "/courses/#{$$course_id}/discussion/comments/#{param}/unvote"
       upload                  : "/courses/#{$$course_id}/discussion/upload"
-      search                  : "/courses/#{$$course_id}/discussion/forum/search"
+      search                  : "/courses/#{$$course_id}/discussion/search"
       tags_autocomplete       : "/courses/#{$$course_id}/discussion/threads/tags/autocomplete"
-      retrieve_discussion     : "/courses/#{$$course_id}/discussion/forum/#{param}/inline"
-      retrieve_single_thread  : "/courses/#{$$course_id}/discussion/forum/#{param}/threads/#{param1}"
+      retrieve_discussion     : "/courses/#{$$course_id}/discussion/#{param}/inline"
+      retrieve_single_thread  : "/courses/#{$$course_id}/discussion/#{param}/#{param1}"
       update_moderator_status : "/courses/#{$$course_id}/discussion/users/#{param}/update_moderator_status"
       openclose_thread        : "/courses/#{$$course_id}/discussion/threads/#{param}/close"
-      permanent_link_thread   : "/courses/#{$$course_id}/discussion/forum/#{param}/threads/#{param1}"
-      permanent_link_comment  : "/courses/#{$$course_id}/discussion/forum/#{param}/threads/#{param1}##{param2}"
-      user_profile            : "/courses/#{$$course_id}/discussion/forum/users/#{param}"
-      followed_threads       : "/courses/#{$$course_id}/discussion/forum/users/#{param}/followed"
-      threads                 : "/courses/#{$$course_id}/discussion/forum"
+      permanent_link_thread   : "/courses/#{$$course_id}/discussion/#{param}/#{param1}"
+      permanent_link_comment  : "/courses/#{$$course_id}/discussion/#{param}/#{param1}##{param2}"
+      user_profile            : "/courses/#{$$course_id}/discussion/users/#{param}"
+      followed_threads       : "/courses/#{$$course_id}/discussion/users/#{param}/followed"
+      threads                 : "/courses/#{$$course_id}/discussion"
     }[name]
 
   @safeAjax: (params) ->