This function can be used to preliminary finish an asynchronous drawing
object. When calling this function, Hollywood will skip to the last
frame of the asynchronous drawing object and finish it. "Finishing"
an asynchronous drawing object means drawing its last frame and running
the finishing code (for example, removing the layer if the asynchronous
drawing object belongs to a RemoveLayerFX() call).
There is a difference between FinishAsyncDraw() and CancelAsyncDraw().
See CancelAsyncDraw for details.. An exception is when layers are enabled.
In that case there is no difference between CancelAsyncDraw() and FinishAsyncDraw().
In case layers are off, you should always use CancelAsyncDraw().