This was a very important update where I fixed a few small but fatal bugs in my

This was a very important update where I fixed a few small but fatal bugs in my
code. I had removed the import of Privilege in mediagoblin.db.migrations, and
this was still necessary and was causing errors. I also made it so that media
deletion by moderators, through reports, actually fully deleted the media,
rather than just deleting the database representation of the media. Lastly, I
fixed a bug in migration that caused a fatal error on login because the UserBan
user_id column was improperly named in it's creation by migration.