Images blocked

In addition to the customers who haven't cleared their caches, we determined that some external sites are inline linking to our images, wasting up to 8Mbps of our bandwidth and a lot of CPU usage with tens of requests per second.

I added new code to prohibit including images, like coins and our logo, from external referers. Feel free to use the images on external sites if you would like, but you'll have to make a copy and provide your own bandwidth starting now.