MFreeQueues [FirstQueue.w,LastQueue.w] ; Free/delete all/range of Queues

Frees all or a range of previously-created queues. If the parameters are omitted
it will free all created chunky Queue objects, otherwise just the range you
specify. When freed, a Queue will be `killed' and the memory for the Queue items
freed so the Queue is effectively empty. If the specified Queues don't exist it
will report an error, but will not report an error when freeing all Queues.