Use the ACE code editor

Couple minor fixes, but the real goal was to add the ACE edtior -- http://ace.c9.io/#nav=about. There was a cool demo at @code4lib that had a contextual MODS editor that I want to play with at some point.

![screen shot 2014-04-01 at 15 18 06](https://cloud.githubusercontent.com/assets/111218/2585349/910d1fee-b9eb-11e3-892b-6e0bc1ad0cf4.png)