Window stacking levels

[Richard Frith-Macdonald]

I have updated the current Window Maker code in the CVS repository to revise 
the known
window stacking levels to match those used in GNUstep, and have modified the 
code to
permit GNUstep applications to specify arbitrary stacking levels for their 
windows.

This should mean that GNUstep applications will now be able to use any stacking 
levels
they like.  In particular we should be able to write nice screensavers and 
dock-like
applications and all that other stuff :-)