Make webpage more aesthetically pleasing

* Update to latest version of Bootstrap
* Create size hierarchy in header area
* Switch to Bootstrap styled navigation
* Use more pleasing whitespace proportions
* Make website more responsive (work on smaller screen sizes)

Here's how it now looks on desktops, not that different, and on smaller screens the site is actually usable now. 
![desktop](https://f.cloud.github.com/assets/929309/1504678/c0c00e8a-48c2-11e3-806d-265bcc695ad2.png)