[Xorg] Damage/Composite + direct rendering clients

[Egbert Eich]

Jim Gettys writes:
 > 
 > Which is why avoiding server grabs is imporant, as much
 > as possible.  It takes a global lock out on the X server and
 > needs to be used with great care.

But you cannot rule out that some legacy client apps don't use server
grabs for strange purposes. 
It may in fact be necessary to make some 'priviledged' clients like
the composition manager immune to server grabs.

Cheers,
	Egbert.