services: slim: Preserve the order of session types.

That makes WindowMaker the default session, by default.

* gnu/services/xorg.scm (xsessions-directory)[builder]: Prepend a number
  in the file name to preserve the order of SESSIONS.
  (slim-service): Augment docstring.
* doc/guix.texi (X Window): Adjust accordingly.

gnu: openexr: Add synopsis.

* gnu/packages/graphics.scm (openexr)[synopsis]: Fill in.
  [description]: Improve.

gnu: samba: Update to 3.6.25.

* gnu/packages/samba.scm (samba): Update to 3.6.25.

gnu: e2fsprogs: Update to 1.42.12.

* gnu/packages/linux.scm (e2fsprogs): Update to 1.42.12.

gnu: icecat: Apply fixes for CVE-2015-{0822,0827,0831,0836}.

* gnu/packages/patches/icecat-CVE-2015-0822.patch,
  gnu/packages/patches/icecat-CVE-2015-0827-pt-1.patch,
  gnu/packages/patches/icecat-CVE-2015-0827-pt-2.patch,
  gnu/packages/patches/icecat-CVE-2015-0827-pt-3.patch,
  gnu/packages/patches/icecat-CVE-2015-0831-pt-1.patch,
  gnu/packages/patches/icecat-CVE-2015-0831-pt-2.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-01.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-02.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-03.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-04.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-05.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-06.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-07.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-08.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-09.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-10.patch,
  gnu/packages/patches/icecat-CVE-2015-0836-pt-11.patch: New files.
* gnu-system.am (dist_patch_DATA): Add them.
* gnu/packages/gnuzilla.scm (icecat)[source]: Add patches.

gnu: Fix luajit installation

* gnu/packages/lua.scm (luajit): Apply 2 patches.
* gnu-system.am (dist_patch_DATA): Register 2 patches.
* gnu/packages/patches/luajit-no_ldconfig.patch: New file.
* gnu/packages/patches/luajit-symlinks.patch: New file.

gnu: Add avidemux.

* gnu/packages/video.scm (avidemux, avidemux-2.5): New variables.

gnu: ffmpeg: Add soxr and twolame as inputs.

* gnu/packages/video.scm (ffmpeg): Add soxr and twolame as inputs.

gnu: nss-mdns: Use /var as the localstatedir.

Reported by Mark H Weaver <mhw@netris.org>
at <http://lists.gnu.org/archive/html/guix-devel/2015-02/msg00686.html>.

* gnu/packages/avahi.scm (nss-mdns)[arguments]: Use
  --localstatedir=/var.

services: nscd: Make sure /var/db/nscd exists.

* gnu/services/base.scm (nscd-service)[activate]: Make /var/db/nscd.

gnu: Add CTL.

* gnu/packages/graphics.scm (ctl): New variable.

gnu: Add OpenEXR and IlmBase.

* gnu/packages/graphics.scm (ilmbase, openexr): New variables.
* gnu/packages/patches/openexr-missing-samples.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.

gnu: Add portaudio.

* gnu/packages/audio.scm (portaudio): New variable.

gnu: Add twolame.

* gnu/packages/audio.scm (twolame): New variable.

gnu: Add soxr.

* gnu/packages/audio.scm (soxr): New variable.

gnu: Add soundtouch.

* gnu/packages/audio.scm (soundtouch): New variable.

gnu: Add libsbsms.

* gnu/packages/audio.scm (libsbsms): New variable.

gnu: Add cpufrequtils.

* gnu/packages/linux.scm (cpufrequtils): New variable.
* gnu/packages/patches/cpufrequtils-fix-aclocal.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.

gnu: Add sysfsutils-1.

* gnu/packages/linux.scm (sysfsutils-1): New variable.

gnu: Add sysfsutils.

* gnu/packages/linux.scm (sysfsutils): New variable.