Solution to Issue #160: Slide Menu Section Headers

This is my proposed solution to theissue/feature request of adding support for menu headers in the slide menu. I attached a photo of this in use in a current ChariTi application:

![menu header example](https://f.cloud.github.com/assets/5115774/1331372/8ec3707a-3553-11e3-9313-1704f2a15c58.png)