New theme - Flat

Hey Thomas!
I loved your project Bootswatch and to test it out I made a new theme 'Flat' which has colors  and few styles based on the Flat UI pack by Designmodo.

Well I'd just like to contribute :)

Here's a peak

![bootswatch flat](https://f.cloud.github.com/assets/971411/462831/360ddece-b4e4-11e2-9639-b4adccfc2ca4.png)