Add some styling around newly included body

Add gutters and a max-width to the new body content

Before: 
![screen shot 2014-09-12 at 15 21 57](https://cloud.githubusercontent.com/assets/68009/4250891/4f2cc8c2-3a88-11e4-9e68-e47d2f745243.png)
![screen shot 2014-09-12 at 15 21 52](https://cloud.githubusercontent.com/assets/68009/4250892/514fed28-3a88-11e4-92c3-e96d1cc227f2.png)

After:
![screen shot 2014-09-12 at 15 19 36](https://cloud.githubusercontent.com/assets/68009/4250896/594b2812-3a88-11e4-9832-82d7dcc388eb.png)
![screen shot 2014-09-12 at 15 19 44](https://cloud.githubusercontent.com/assets/68009/4250897/5ad72cda-3a88-11e4-854f-d447cf6b1c3c.png)