2.10 bugfixes

This is a bugfixing branch for 2.10.  I'm putting it up here for review, but its not going to sit for a long time.  I will pull it myself in a few days or so.  

-  Fixed a bug where gateway answer prefixes were being rendered by mathjax in the Show Past Answers page
-  Fixed a bug where long descriptions didn't wrap on the homework sets editor
-  Fixed a bug where some gateway tests didnt have their description tooltips.