Upgrade to SQLA 0.9.4.

0.8.4 fixed the thing where Alembic would autogenerate a fuckload of
drop index/create constraint pairs, and while I was at it I figured
I may as well test if the latest version works.  It seems ot.
Validate accounts by checking people's forum profiles. #13

A bunch of semi-related, little, miscellaneous things got caught up in
here, too.