Reviewboard Account Registration

[Tim Flink]

In the last couple days, about 25 spam users have registered in our
reviewboard instance. I've already deleted the accounts before they
could do any damage but I've also disabled new user registration so the
problem doesn't continue.

I'm happy to grant new accounts to real people, though. If you'd like
an account, just let me know and hopefully we'll be able to migrate to
fas-openid auth soon.

Tim