[Openal] Distance model

[Garin Hiebert]

WRT the earlier question about AL_GAIN showing up in the formulas --  
if it's showing up in a distance formula in the 1.1 spec, that's a  
mistake -- I tried to get all that cleaned-up with the new spec...   
The gain being calculated in the distance formulas is just a distance- 
related gain factor (to be multiplied later on by the source's gain).

> I'm looking at the SetNonEAXSourceLevels function.  It appears to  
> implement the distance model.  But I have some questions:

I'll take a look at it tomorrow (or maybe Dan saw your email and is  
looking at it...).  It seems plausible that there's a mistake with  
the DS3D backend with that model, since that's a case where a  
workaround would have to be in there (DS3D uses a clamped model  
natively).

Garin