gnu: gnupg: Update to 2.0.25 and 1.4.18.

* gnu/packages/gnupg.scm (gnupg): Update to 2.0.25.
  (gnupg-1): Update to 1.4.18.

gnu: Add maxima.

* gnu/packages/maths.scm (maxima): New variable.

gnu: Add gcl.

* gnu-system.am (GNU_SYSTEM_MODULES): Add new package.
* gnu/packages/lisp.scm: New file.

gnu: Avoid circular dependency among modules.

Reported by Alex Kost <alezost@gmail.com>.

* gnu/packages/python.scm: Don't use #:select for (gnu packages zip).

gnu: Add gegl and gimp

* gnu/packages/gimp.scm (gegl, gimp): New variables.

gnu: Add youtube-dl.

* gnu/packages/video.scm (youtube-dl): New variable.

gnu: pdf: Add PoDoFo.

* gnu/packages/pdf.scm (podofo): New variable.

gnu: Add cmatrix.

* gnu/packages/games.scm (cmatrix):  New variable.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add node.

* gnu-system.am (GNU_SYSTEM_MODULES): Add new package.
* gnu/packages/node.scm: New file.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add jrnl, python-pycrypto, python-keyring, python-parsedatetime, and python-tzlocal.

* gnu/packages/jrnl.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.
* gnu/packages/python.scm (python-pycrypto, python-keyring,
  python-dateutil-2, python-parsedatetime, python-tzlocal): New
  variables.

gnu: Add behave, python-six, python-enum34, python-parse-type, and python-parse.

* gnu/packages/python.scm (python-six, python-enum34, python-parse-type,
  python-parse, behave): New variables.

gnu: Add goffice and gnumeric

gnu/packages/gnome.scm (goffice, gnumeric): New variables.

gnu: Add ncmpcpp.

* gnu/packages/mpd.scm (ncmpcpp): New variable.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: guix: Use the development version by default.

* gnu/packages/package-management.scm (guix): Rename to...
  (guix-0.6): ... this.
  (guix-devel): Rename to...
  (guix): ... this.  Replace references to 'guix' by references to
  'guix-0.6'.

gnu: guix: Add development version.

* gnu/packages/package-management.scm (guix-devel): New variable.

gnu: Adjust for (gnu packages image) merger.

* gnu/packages/aidc.scm: Use (gnu packages image).

gnu: Add talkfilters.

* gnu/packages/games.scm (talkfilters): New variable.

gnu: Add qrencode.

* gnu/packages/aidc.scm (qrencode): New variable.

gnu: Consolidate libjpeg, libpng, and libtiff into one module.

* gnu/packages/image.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add image.scm and remove libjpeg.scm,
  libpng.scm, and libtiff.scm.
* gnu/packages/libjpeg.scm, gnu/packages/libpng.scm, gnu/packages/libtiff.scm:
  Delete files.
* gnu/packages/emacs.scm gnu/packages/games.scm, gnu/packages/gd.scm,
  gnu/packages/geeqie.scm, gnu/packages/ghostscript.scm,
  gnu/packages/gimp.scm, gnu/packages/gnome.scm, gnu/packages/gnunet.scm,
  gnu/packages/gnustep.scm, gnu/packages/gnuzilla.scm,
  gnu/packages/graphviz.scm, gnu/packages/gtk.scm,
  gnu/packages/imagemagick.scm, gnu/packages/inkscape.scm,
  gnu/packages/netpbm.scm, gnu/packages/pdf.scm, gnu/packages/plotutils.scm,
  gnu/packages/qemu.scm, gnu/packages/qt.scm, gnu/packages/scheme.scm,
  gnu/packages/sdl.scm, gnu/packages/slim.scm, gnu/packages/tcl.scm,
  gnu/packages/texlive.scm, gnu/packages/video.scm, gnu/packages/xiph.scm,
  gnu/packages/xorg.scm: Use (gnu packages image) module.

gnu: Enable libvpx support in ffmpeg.

* gnu/packages/video.scm (ffmpeg): Add libvpx input.