Added Monokai-chris which is the same as Monokai but with a darker backg...

...round

Monokai-chris
![monokai-chris](https://cloud.githubusercontent.com/assets/597140/2635113/ddc8fe9e-be81-11e3-9979-b338d6efb390.jpeg)

Monokai
![monokai](https://cloud.githubusercontent.com/assets/597140/2635136/06671552-be82-11e3-96f5-19843af24751.jpeg)


Background has been updated to #1e1e1e which I find easier on the eyes.