[Openal] OpenAL and Vista

[Garin Hiebert]

> I also had a couple of users who told me the sound output would be too quiet 
> with no way to turn it louder, even when raising all bars in the main windows 
> mixer settings.
>   

The common thread for the "no gain adjustability" problem seems to be 
Realtek drivers -- there are Realtek drivers out there (not sure if the 
latest fix the problem) which claim EAX 2 support but don't actually 
implement the calls.  For reasons I won't bother delving into, when EAX 
2 is available, it's actually important that the calls work so that 
gains come out correctly.  For these devices, the "Generic Software" 
device should be selected.

If there are other repeatable, testable cases which don't fit this 
scenario, then we'd like to take a look at them and fix the issues. 

Garin