layer pane now matches help pane

Looks like this: 

![screen shot 2013-11-05 at 5 57 25 pm](https://f.cloud.github.com/assets/108094/1478553/b25aa4ec-466d-11e3-9470-052df0e0ee81.png)

Notes:

- Clicking on right map tool links now closes the help panel. Was weird once the layers list looked like the help overlay to have them both open at the same time.
- There are now top tooltips on layers. Feels fine to me. Having tooltips overflow-x + allowing content to overflow-y isn't possible :(