Engine: + Split PlaySound into PlaySound and LoopSound + Added overloaded versions of PlaySound/LoopSound that won't require voicepack parameter + LoopSound now allows multiple copies of the same sound to play looped and returns the channel used for playback (to stop them later) + StopSound now allows either a specific sound (single playback) or channel (single playback as well as looped playback) to be stopped + SoundChannel attribute for Gears to be used when looping sounds