[D3D] Added native and emulated S3TC support (take 2)

[Lionel Ulmer]

> I've only mentionned the libtxc_dxtn.so library for software 
> decompression when the video card does not support S3TC.
> Maybe Lionel can say if we can add more precise information i.e 
> reference to the DRI project.

Well, the page where you can download it is the third Google link when
searching for 'libtxc_dxtn'.

So I think the information there is enough :-)

        Lionel

PS: thanks for the edits, will be able to test the final version now that
    it's commited :-)

-- 
		 Lionel Ulmer - http://www.bbrox.org/