Fixed FB login.

The main problem was the configuration on FB.

I also changed the callback handler to return any user with the given
email, no matter how they may have logged in in the past, and I did a
little refactoring.

I also re-enabled the FB login icon.
Removed the FB authentication from the configuration.
Update the provider everytime a user logs in and use that avatar.

This is so we get the FB avatar whenever the user logs in from FB.
Updates our humans.txt file.
Fixed facet frequency sorting.

Because, yanno, I always want to sort numbers by converting them to
strings and sorting lexographically.

NOT.

Geez. JavaScript. And to think this is the new assembly.

Rant over.

Fixes #295.
Merge branch 'develop' of github.com:scholarslab/prism into develop
Added my information to humans.txt.

And removed trailing WS.
gif
Updated ActionMailer gem

Updates ActionMailer gem to protect against a possible DoS vulnerability (CVE-2013-4389). See http://seclists.org/oss-sec/2013/q4/118