This caused the PFNGLMULTITEXCOORD2FPROC definition to be moved out of the
GL_VERSION_1_3_DEPRECATED block. However, since <GL/gl.h> also defines
GL_VERSION_1_3 to 1, the definitions in <GL/glext.h> are then not enabled,
thus leaving PFNGLMULTITEXCOORD2FPROC undefined as well.

Provide a PFNGLMULTITEXCOORD2FPROC replacement as an interim solution for
newer versions of the <GL/glext.h> header.

Patch taken from: http://gitorious.org/vaapi/gstreamer-vaapi/commit/5db2e93d3c930fd8470cfdcd26f514d1cebc59a0?format=patchSigned-off-by: Jean-Paul Saman <jpsaman@videolan.org>