Bug#443936: xserver-xorg-video-mga: windowmaker and 1.9.99 get along terribly

[kls <debbts@eamp.org>]

> > > The problem could related to the acceleration architecture. You're using
> > > the default right now (XAA). Does it help if you add:
[...]
> > > Or maybe the new architecture EXA would be better (I don't know how good
> > > it is in the mga driver so far). Does it help if you add
> > >     Option "AccelMethod" "EXA"
> > > instead of the above NoAccel line?
[...]
> At the moment, MGA's EXA implementation is only usable if you use
>   Option "MigrationHeuristic" "greedy"

So I've tried using windowmaker with EXA (using greedy) and it's
faster than plain XAA (about 200%), although I want to think that it's
slower than in the past, and it is definitely slower than w/ openbox.

If I start xcompmgr, it is effectively the same (slow exposes &c)
speed as before, but windowmaker has effectively all its decorations
100% transparent (with lettering inside opaque). Using transset to set
non-100% opacity approximately does the right thing, but returning it
to 100% opacity reverts to the original incorrect rendering. 

 - robert