Radar for finding players using nicks

![screen shot 2013-12-18 at 10 40 06 am](https://f.cloud.github.com/assets/4820949/1770916/c86bf9ec-67a2-11e3-987c-915c75144cfa.jpg)


Radar overlay around the crosshair, based on distance to other players
on the server, with direction indicated by angle of other players from
current player. Updates in realtime