Added a troubleshooting page.

This helps tell you at what level of the stack a problem is occuring.

It will try...
The Content API
The application specific load balancer
The router load balancer
www.theguardian.com

cc @shufgy @rexcooper 

![introuble](https://f.cloud.github.com/assets/76709/1977110/c881cb34-8393-11e3-8ce3-a6fa416d175c.png)


![troubleshoot](https://f.cloud.github.com/assets/76709/1977111/cc7829ea-8393-11e3-8ef9-a831082f1001.png)