more group progress, UI getting there, controller mostly done

changed it so notify moderators goes to the moderators group
allow admins to grant self moderation and revoke self moderation

lib/post_creator.rb

@@ -21,6 +21,7 @@ class PostCreator
   #     archetype             - Topic archetype
   #     category              - Category to assign to topic
   #     target_usernames      - comma delimited list of usernames for membership (private message)
+  #     target_group_names    - comma delimited list of groups for membership (private message)
   #     meta_data             - Topic meta data hash
   def initialize(user, opts)
     # TODO: we should reload user in case it is tainted, should take in a user_id as opposed to user