Socket server improvements

This includes several improvements to the system based on experience with the first load test as well as an experimental rearchitecting of the socket server itself to use a single greenlet and ignore the receive buffer.

I would like to have the active connection count reported to graphite somehow, but have yet to work out the cleanest solution for doing so; Gauges seem like the closest bet, but don't seem too friendly with the idea of multiple workers reporting their own values (without having lots of separate stats).