Changed RETINA branding font

Changed "RETINA" brand to use Orbitron font across the website.  What do you guys think of using that font in the logo?  I had already changed it on part of the About page, but you can see the difference in the navbar and page heading.


Original:
![screen shot](https://cloud.githubusercontent.com/assets/3259614/4262941/bc9c4dde-3bc2-11e4-8b8b-9efbaad5cd0a.png)
Change:
![screen shot 2014-09-14 at 12 30 51 am](https://cloud.githubusercontent.com/assets/3259614/4263069/f1db538c-3bc7-11e4-8cc0-1330d70659c1.png)

Usage:
`<span class="retina-brand">RETINA</span>`
I likely did that when trying to get z-index to work (It actually just needed position: relative) and forgot to change it.  I updated it to one div.