MUnQueue QueueNumber.w[,BitmapNumber.w] ; UnQueue the queued objects and flush the queue

Un-Queues the specified Queue to the current chunky Bitmap. If the Bitmap parameter
is omitted a `clearscreen' operation will be performed (to Colour 0) in all of the
areas that have been recorded into the Queue list. If the Bitmap parameter is
specified a chunky Bitmap will be used as a background store, from which the
areas recorded in the Queue will be blitted to the currently used Bitmap instead
of just performing a clearscreen. Once all items have been un-queued, the Queue
will be completely flushed.