SetUpMacOS.cmake: let FindX11.cmake find X11 headers on Mac OS X
SetUpMacOS.cmake: let FindX11.cmake find X11 headers on Mac OS X

FindX11.cmake already has the path being added here listed before
/usr/include, so we do not need to add it. XQuartz headers are
actually in /opt/X11/include, and /usr/X11R6 is a link to /opt/X11.

olifre/root,olifre/root,olifre/root,karies/root,root-mirror/root,karies/root,olifre/root,karies/root,olifre/root,root-mirror/root,olifre/root,karies/root,olifre/root,karies/root,olifre/root,root-mirror/root,karies/root,root-mirror/root,root-mirror/root,root-mirror/root,root-mirror/root,karies/root,root-mirror/root,karies/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,karies/root,karies/root,root-mirror/root,olifre/root,olifre/root