First attempt at sprite animation.
Merge remote-tracking branch 'origin/master' into animated_sprites

Conflicts:
	public/js/app.js
	src/pixi_wrapper.coffee
	src/rts_world.coffee
Remove trailing commas from the robot spritesheet json.
Rejigger spritesheet and start refactor
tmp playground
CommandQueue
Merge branch 'master' into place_your_unit

Conflicts:
	public/js/app.js