Exclusive window manager for -multiwindow

[Harold L Hunt II]

Takuma,

> I have committed a change for -multiwindow window manager
> to the xorg tree.  Now the wm should be able to detect
> another wm and the others can detect it.  This change
> corresponds to the second item (Window manager detection)
> in the To-Do list.
> 
> To do so the internal wm grabs ButtonPressMask, which is
> allowed only one client at once.  Thus other wm's will fail
> to obtain the mask and immediately exit when invoked.
> 
> Takuma Murakami

I am taking this item off the To Do list.  Thanks so much for fixing it. 
  I tested your fix and it works fine with twm.  Doing a 'startkde' on a 
remote box does not fail like twm does... it still works and has weird 
behavior.  I wonder if there is something else that we need to do to 
work with modern window managers?  In any case, your fix is better than 
what we had before.  :)

Harold