* Forums are disowned on user account deletion (their owner_id=0)
* A forum without an owner shows a notice at the bottom with a link to petition
to adopt the forum. It goes to the Contact form with a special subject.
* Note: there is no easy way to re-assign ownership yet other than a direct
database query.
* Code cleanup
* Alphabetize the DB.AutoMigrate tables.
* Delete more things on user deletion: forum_memberships, admin_group_users
* Vacuum worker to clean up orphaned polls after the threads are removed
* Add the Contact page where users can contact the site admins for feedback or
to report a problematic user, photo or message.
* Reports go into the admin Feedback table.
* Admin nav bar indicates number of unread feedbacks.
* Add "Report" button to profile pages, photo cards, and the top of Direct
Message threads.
Misc changes:
* Send emails out asynchronously for more responsive page loads.
