Add missing <ul>[…]</ul> around list elements in sidebar TOC.

**Before:**
![saltdocs-toc-list-before](https://cloud.githubusercontent.com/assets/48491/3543701/c3f85aa0-0864-11e4-8c23-55a19443c01d.png)

**After:**
![saltdocs-toc-list-after](https://cloud.githubusercontent.com/assets/48491/3543703/c98cb1e6-0864-11e4-96ce-ede20231153f.png)