still many warnings from Mesa

[Lionel Ulmer]

> Could someone please have a look at addressing these?

Well, I think the only way to safely remove these are by using
--disable-opengl.

Ie I will detect that one has 'ABI-compliant' GL headers (ie that it defines
the glXGetProcAddressARB / multi-texture prototypes) and disable OpenGL
build if not.

I know it's a Linux only ABI but well, people on other platforms can fix the
issue if they need it to be fixed :-)

         Lionel

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