put license text in lighter container for better contrast

This addresses the color contrast part (but not the font stack part) of #85.

I've put the license text in a lighter container as @cobyism mentioned. I needed to add some padding to this container, so I've widened the overall page container to account for this.

I also unboxed the sidebar "How to apply this license" callout. since it looked a bit cluttered with the new license text box.

![screen shot 2013-09-25 at 8 57 22 am](https://f.cloud.github.com/assets/6104/1209185/9b253738-25e3-11e3-9498-8263bc082fbb.png)

/cc @Haacked @anshin