[oglbase-discuss] Updated GL_EXT_get_proc_address spec

[Brian Paul]

I've made a few updates to this spec with respect to the last of the
discussion.

This spec and related ones are at http://www.mesa3d.org/misc/

The major change reflects the decision that glGetProcAddressEXT returns
a context-independent pointer.  I also changed the Errors section
(calling glGetProcAddress between glBegin/glEnd is illegal but may not
generate an error).

I believe the only outstanding issue is whether glGetProcAddressEXT
is indeed the right function name.  The alternative is to use
glXGetProcAddressEXT to return pointers to core GL functions in
addition to GLX functions.

I'm in favor of the former (having glGetProcAddressEXT).

-Brian