Added architecture diagram for cloud foundry internals

![welcome to cloud foundry documentation 2013-05-22 15-30-54](https://f.cloud.github.com/assets/2016/551634/447cd790-c32f-11e2-9ddd-4e75e46e08a5.png)

![cloud foundry architecture diagram 2013-05-22 15-31-17](https://f.cloud.github.com/assets/2016/551637/527e1354-c32f-11e2-8319-14e386d4c0d3.png)