test case demonstrating PeekMessage give up timeslices

[Felix Nawothnig]

Oliver Mössinger wrote:
> We changed our program to avoid the needless polling (only two PeekMessage are
> needet then). We add also the PM_NOYIELD. This gives back the reaction of the
> program if some other process consumes process time. But the speed is more
> reduced than windows.

So we actually got a real world app which depends (depended, but we 
don't want apps getting fixed for Wine, right?) on PeekMessage not 
giving away timeslices?

Felix