Fixed JSON formatting and highlighting

It really looks broken otherwise.

Before:
![2014-03-28_2211](https://cloud.githubusercontent.com/assets/1444210/2553375/901c0da6-b6a4-11e3-9077-600a47e3e3d1.png)

After:
![2014-03-28_2210](https://cloud.githubusercontent.com/assets/1444210/2553372/874384b6-b6a4-11e3-8c2d-0816b054d484.png)