More nav tweaks

Some slight adjustments to navigation appearance, removing some more messy code, and removing some variables that were unused across Neue and the main DS app.

Before:
![screen shot 2014-07-02 at 10 47 57 am](https://cloud.githubusercontent.com/assets/583202/3457338/df1fb008-01f7-11e4-8a0a-355dbe4489ea.png)

After:
![screen shot 2014-07-02 at 10 49 58 am](https://cloud.githubusercontent.com/assets/583202/3457380/298a446e-01f8-11e4-81e6-b02bd4fc8d1a.png)