Require X11 check before OpenGL header check on Mac OS X (since whether or not we use X11 changes how to include the GL headers, and needs /usr/X11R6/include to be added to the include path).
Require X11 check before OpenGL header check on Mac OS X (since
whether or not we use X11 changes how to include the GL headers,
and needs /usr/X11R6/include to be added to the include path).

Alexpux/simacros,Alexpux/simacros,Alexpux/simacros,Alexpux/simacros