[Openal] new router library for Windows

[Garin Hiebert]

An announcement has just been posted to the OpenAL site saying that a
new beta OpenAL installer is available containing a routable OpenAL
library.  This new library supports a new enumeration extension to
OpenAL which allows an application to enumerate the available OpenAL
devices and select  from among them.  For an example of how this works,
take a look at the initialization code in altest out of CVS
(openal/demos/altest).  A pre-compiled version of ALTest is also
available off the website next to the link to the beta installer.

Thanks go out to Stephen Holmes and Daniel Peacock for their work on the
router DLL and wrapper DLL that are included in this installer!

If you use this beta installer, please send me an email telling me how
things went.  I think we'll be able to make this the mainstream codebase
very quickly, but I need some feedback first...

Garin