- Add build system for xserver/xorg/hw/xfree86/dri
- Add glcore.h to symlink.sh
- Symlink.sh: add some more DRI files, symlink glcore.h from
    extras/Mesa/include/GL/internal to proto/GL
- proto/GL/Makefile.am: install glcore.h
- xf86-video-ark: s/module-dir/xorg-module-dir/