FEATURE: User page refactor

Re-organise user page so it is easier to find interesting info
split it into tabs

- Introduce notifications and messages tabs
- Stop couting stuff for the user page to speed up rendering
- Suppress more information when viewing your own profile

app/serializers/basic_group_serializer.rb

@@ -11,7 +11,8 @@ class BasicGroupSerializer < ApplicationSerializer
              :title,
              :grant_trust_level,
              :incoming_email,
-             :notification_level
+             :notification_level,
+             :has_messages
 
   def include_incoming_email?
     scope.is_staff?