Add avatar to topics list.
Reply form use all available space.
Add flag to mark topics as private.
Repair test.
Display only public topics in the topics pages.
Add code to get private topics targeted to user.
Allow to limit the visibility of replies of an user in a private topic.
Fix permissions when replying to topics.
Add association to reply to a topic.
Allow replies add to fail validation properly.
Fix test.
Allow user to have private discussions.