ports/76257: nvidia_driver breaks xorg-clients build

[Mikhail Teterin]

	[CC-ing the author of xdriinfo]

Felix, please, take a look at:

	http://www.freebsd.org/cgi/query-pr.cgi?pr=ports/76257

The patch is wrong -- the program compiles, but does
not work (``libgGL is too old'').

The problem is, NVidia's GLX-implementation is version
1.3, while XOrg expects (and provides) 1.4.

However, it may be possible to obtain the information,
which the xdriinfo.c is trying to obtain with these two
glXGetProcAddress-calls, using glXGetProcAddressARB or
some other pre-GLX_1_4 method.

Then we can have xdriinfo, which works with all of GL
implementations available for FreeBSD.

Finally, what's in xdriinfo, that's not in glxinfo?

	-mi