MMakeCookies [FirstShape.w,LastShape.w] ; Make cookies for all/range of shapes

Initialises (if necessary) and generates cookies for all or a range of chunky
Shape objects. If the cookie doesn't yet exist it will be allocated. The cookie
will be generated based on the contents of the Shape's image. If the parameters
are omitted, all currently created chunnky Shapes will have cookies generated.
The area of a Shape used to make a cookie can be cropped using the Shape's clip
window.