Fix issue with tag names containing a '-'

This fixes the issue so that highlighting of elements with names containing a '-' go from this:

![screen shot 2014-05-09 at 7 04 34 pm](https://cloud.githubusercontent.com/assets/1730681/2934931/195918c0-d7e3-11e3-89f3-e56cbde2e431.png)

to this:

![screen shot 2014-05-09 at 7 18 26 pm](https://cloud.githubusercontent.com/assets/1730681/2934911/8104a342-d7e1-11e3-8b42-a310f4f428e1.png)