mmsystem: Improve 16 bit mapping for MCI_WHERE/PUT/FREEZE/UNFREEZE.

Hi,

Damjan Jovanovic wrote:
> In the meanwhile I've found another problem: mciavi32 always deadlocks
> when MCI_WAIT is not set:[...] ShowWindow()

Looks like bug #21060 and the others
http://bugs.winehq.org/show_bug.cgi?id=21060#c2
- bug #12908, bug #15669, bug #18363 involving ShowWindow;
- bug #14785, bug #21060 involving EnterCriticalSection.
But perhaps there's only a single issue.

It would be nice if somebody who knows about windows and their
messages would look at these.

Regards,
 Jörg Höhle