Ui tweaks - full-width, hero unit, and navbar readability

Here are a few tweaks to the front page, and navbar.  Check the screenshot below.  I've also left each change as it's own branch so that you can pick and choose which changes you want if you don't want everything. 

![screenshot from 2013-07-26 23 54 14](https://f.cloud.github.com/assets/509382/866371/945c1752-f670-11e2-8a6f-15fe71cad04f.png)