[Openal] new Windows SDK and installer

[Garin Hiebert]

The new Windows SDK and installers are published at 
developer.creative.com (direct link off the AL site's main page in the 
News section).  For the libraries, here are the main changes:

- Win98 crash bug fixed
- speed improvements with "Generic Software" device
- fixed source gain issue with stereo buffers
- router's search path now includes the router's directory (matching the 
documentation on the OpenAL site)
- Vista default device and enumeration fixes -- we're now working really 
well on Vista
- capture can now be used independently of playback

The SDK has minor improvements in the integrated Visual Studio help, 
some small example code fixes, and the new OpenAL installer...

Garin