UI Changes to Header

![screen shot 2014-04-21 at 21 34 45](https://cloud.githubusercontent.com/assets/4593664/2758671/7e64a8f4-c994-11e3-81c5-1a9a7ee22443.png)

Made the header of the page relative positioned rather than fixed to improve the usability and legibility throughout. Also simplified visual cruft in the header by removed border-radius and partial widths on both the header and sub-header.