New xorg-updates branch pushed

[Mark H Weaver]

Hello Guix!

I've pushed a new branch 'xorg-updates' which updates almost every
package in xorg.scm, as well as mesa, dbus, glib, pixman, cairo,
poppler, inkscape, and a few others.

My original purpose was to apply security fixes mentioned here:

  http://www.x.org/wiki/Development/Security/Advisory-2014-12-09/

but I decided it was a better use of my time to upgrade xorg-server to
the latest pre-release (which contains the fixes) than to try to
backport them to our old xorg-server.  This required updating the *proto
packages, which in turn forced a rebuild of the X libraries and
everything built on them, so I decided I might as well update most of
xorg.scm while I was at it.

I've been running with these patches on my own system for the last day
or so, and it's working very well so far.  The X server now uses
xf86-input-evdev, which among other things enables hotplugging of input
devices.  xf86-video-modesetting also now works.  I was also able to
resurrect xf86-video-geode, thanks to a new upstream release.

Two drivers no longer compile: xf86-video-ast and xf86-video-newport.
They both try to include xaa.h, which has apparently been removed from
the server, although I confess I didn't look too deeply into it.

Most of the commits are fairly straightforward, but I wanted to call
attention to a few points:

* Wherever possible, I changed the source URIs to
  mirror://xorg/individual/.  For most of the package updates this was
  required, and then for consistency, in the final commit I changed all
  of the URIs for the packages I didn't update.  I made it the last
  commit so it will be easy to remove if there are objections :)

* Many video drivers needed patches.  Most of the patches are for two
  recurrent problems:

   * mibstore.h has been removed in the X server, and 10 of the video
     drivers haven't yet been updated.  Fixing this requires patches
     like this:

     
http://git.savannah.gnu.org/cgit/guix.git/tree/gnu/packages/patches/xf86-video-nv-remove-mibstore.patch?h=xorg-updates

   * There's an incompatibility between glibc-2.20 and the os.h header
     in the xorg-server package.  Until they fix this properly, a
     simple workaround is to include <xorg-server.h> before including
     the headers for the internal X driver API, as done here:

     
http://git.savannah.gnu.org/cgit/guix.git/tree/gnu/packages/patches/xf86-video-intel-glibc-2.20.patch?h=xorg-updates

   * Related to the problem above, some video drivers checked for the
     exa.h header in their configure scripts, and the test compilation
     fails for the same reason as above.  My workaround was to hack the
     configure script to include <xorg-server.h> in the test program,
     using patches like this:

     
http://git.savannah.gnu.org/cgit/guix.git/tree/gnu/packages/patches/xf86-video-mach64-glibc-2.20.patch?h=xorg-updates

I've asked Hydra to build this new branch, and when it's done building
(or close to it) I plan to merge it into master.

In the meantime, if anyone feels inspired to review these 116 commits,
your comments and suggestions are welcome.  Testing would also be very
helpful, as I was only able to test on my Libreboot X60 laptop with
intel graphics.

       Mark