Major mmdevapi and winmm audio bugs

[Juan Lang]

Hi Andrew,

one small contribution:

> Winmm's timer functions use poll() with a timeout value, subtracting
> the time elapsed curing the callback. This works quite well in dsound.
>
> The Win32 API also provides the SetTimer API. But that depends on a
> message queue, which is a hassle I don't know if we want to bother
> with in the drivers (plus, it may be no more reliable than the
> TimerQueues).

Using SetTimer is not the way you want to go.  Its timing is
unpredictable and its interface strange.  I'd stay away from it.
--Juan