Fixed hidden navbar dropdowns on mobiles, corrected header.

Currently drowdowns are hidden/cut-off on mobile devices. This way they are shown. Save because only applied if the menu is actually open, in that stage there is no need for `overflow: hidden;`

Also there was a header text copy pasted that was wrong.

Before:
![bs_nav_cutoff](https://f.cloud.github.com/assets/1780826/462923/e193fb3c-b4f5-11e2-8ff4-5bc99733d9b5.png)

After:
![bs_nav_fixed](https://f.cloud.github.com/assets/1780826/462924/eaafdd3a-b4f5-11e2-83d8-9d777032584d.png)