Move SUL dropdown menu to top nav bar

Fixes #365 

![screen shot 2014-07-07 at 10 24 52 pm](https://cloud.githubusercontent.com/assets/1656824/3505502/3e47f740-0660-11e4-82b8-0546b794f98e.png)
![screen shot 2014-07-07 at 10 25 00 pm](https://cloud.githubusercontent.com/assets/1656824/3505503/3fa7b7ce-0660-11e4-9173-291d1dd2d3f6.png)

Positioning of top menu on various sizes can be addressed with #421 
Hey can we ship this? #422 depends on this, and I don't want to rebase both...  I have a pr queued up to fix #421 and another issue that @jvine pointed out that removing the `width: 100%` introduced.