Mesa source no longer required when building Xorg

[Kristian Høgsberg]

Hi,

I just pushed a couple of patches on top of George Sapountzis' cool
dri swrast work, that copies the glapi generated files from mesa into
the glx module and drops the last bit of the symlinking machinery.  We
can now build the xserver without any reference to the mesa tree, but
it does require mesa to be installed for the dri interface headers.
Furthermore, mesa can now build the swrast dri driver without any
xserver installed, we should be able to boot strap the entire stack
much easier now:

  build mesa, requires xlib and xext for glx protocol in libGL, libdrm
for dri drivers.
  build xserver
  ...
  profit!

Also, since the only thing in GL/ in the server was the glx
subdirectory (well, after moving the GL/windows dead weight to
hw/xwin/glx, anyways), I pulled that one level and dropped the GL
directory.

cheers
Kristian