Navigation drawer (squashed and rebased).
This is @ernir's work on #30 (closed) and #181 (closed), rebased onto master with recent changes to ConversationActivity and ForumListActivity ported to the respective fragments.
This is @ernir's work on #30 (closed) and #181 (closed), rebased onto master with recent changes to ConversationActivity and ForumListActivity ported to the respective fragments.