* Adding methods KX_GameObject.stopAction() and KX_GameObject.isPlayingAction(). * Made all layer arguments optional. This means I had to change setActionFrame(layer, frame) to setActionFrame(frame, layer=0). This seems a little backwards to me, but I guess that's what you get with optional arguments. Also, this will break existing scripts. * Made sure to check user supplied layer values on all action methods. Previously this was only done for playAction(). * Fixed a few newline issues.