Starts a sprite animating for 'repeatCount' times through the sequence specified. You can specify any number of frames of animation in the list (limited only by memory).
The delay is specified in frames, the frame is specified as an index into the sprite's current bank (exactly the same as with the sprite command).
Once started the animation will continue indefinitely until it either completes, or another animation is started. You can start an emtpy animation to stop the animation.