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

* gnu/system.scm (<operating-system>)[file-systems]: Remove default.
  [locale]: Add default value.

* guix/scripts/system.scm (%system-profile): New variable.
  (switch-to-system, previous-grub-entries): New procedures.
  (unless-file-not-found): New macro.
  (show-help): Add 'reconfigure'.
  (guix-system): Handle it.
* gnu/system.scm: Export 'operating-system-activation-script'.
* doc/guix.texi (Invoking guix system): Document it.

This is a followup to e2fcc23a.  The /etc/group file would be cleared
when booting.

* guix/build/activation.scm (activate-users+groups)[touch]: Rewrite so
  it does not wipe out FILE's contents.

* guix/scripts/system.scm (read-operating-system) <catch handler>: Add
  case for 'syntax-error'.  Correct message for default case.
* guix/scripts/offload.scm (build-machines) <catch handler>: Add case
  for 'syntax-error'.
* tests/guix-system.sh: New file.
* Makefile.am (SH_TESTS): Add it.

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

* gnu/packages/gl.scm (guile-opengl): New variable.

* gnu/packages/video.scm (libvpx): New variable.

* gnu/packages/aidc.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

* gnu/system.scm (operating-system-grub.cfg): Add 'old-entries'
  parameter.  Pass it to 'grub-configuration-file'.
* gnu/system/grub.scm (grub-configuration-file): Add #:old-entries
  parameter.  Honor it.

* gnu/system.scm (operating-system-parameters-file): New procedure.
  (operating-system-derivation): Use it to produce a 'parameters' files.

* gnu/system.scm (kernel->grub-label): New procedure.
  (operating-system-grub.cfg): Use it.

* gnu/packages/cursynth.scm (cursynth)[source]: Upgrade to 1.5.  New
  'patches' field.
* gnu/packages/patches/cursynth-wave-rand.patch: New patch.
* gnu-system.am (dist_patch_DATA): Add it.

* gnu/packages/gnunet.scm (libmicrohttpd): Upgrade to 0.9.37.

* gnu/packages/gnupg.scm (gnupg): Upgrade to 2.0.24.
  (gnupg-1): Upgrade to 1.4.17.

* gnu/packages/gnupg.scm (libgpg-error): Upgrade to 1.13.

* gnu/packages/nano.scm (nano): Upgrade to 2.3.4.

* gnu/packages/lightning.scm (lightning): Upgrade to 2.0.4.

* gnu/packages/disk.scm (ddrescue): Upgrade to 1.18.1.

* gnu/packages/guile.scm (mcron): Upgrade to 1.0.8.

* gnu/packages/gnutls.scm (libtasn1): Upgrade to 3.6.

* gnu/packages/nettle.scm (nettle-3): New variable.

* gnu/packages/parallel.scm (parallel)[source]: Upgrade to 20140622.

* gnu/packages/moe.scm (moe)[source]: Upgrade to 1.6.
  Add 'native-inputs' field.

* guix/scripts/system.scm (install): Wrap 'install-grub' call in
  'false-if-exception'.  This is a followup to 641f9a2a.

* gnu/packages/pulseaudio.scm (json-c): Move to...
* gnu/packages/web.scm (json-c): ... here.  New variable.

* gnu/packages/pulseaudio.scm (json-c)[source]: Upgrade to 0.12.  Add
  'modules' and 'snippet' fields.

* gnu/system/install.scm (installation-services): Call 'udev-service'.

* gnu/services/base.scm (udev-service): New procedure.
  (%base-services): Use it.
* gnu/system.scm (%base-packages): Add UDEV.

* gnu/packages/mail.scm (notmuch): New variable.

gnu/packages/screen.scm (dtach): New variable.

* gnu/packages/samba.scm (talloc): New variable.

* gnu/system/install.scm (installation-os): Remove 'groups' field.
* build-aux/hydra/demo-os.scm: Likewise.

* gnu/system/shadow.scm (%base-groups): New variable.
* gnu/system.scm (<operating-system>)[groups]: Use it as the default.

* gnu/system/shadow.scm (<user-group>)[members]: Remove field.
* gnu/system/install.scm (installation-os)[users]: Remove 'members'
  fields.  Use 'supplementary-groups' for 'guest'.
* build-aux/hydra/demo-os.scm (users): Likewise.
* gnu/services/base.scm (guix-service): Remove 'members' field.

* gnu/packages/patches/kmod-module-directory.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/linux.scm (kmod)[origin]: Use it.

* gnu/packages/linux.scm (udev): New variable.
* gnu/packages/patches/udev-gir-libtool.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

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

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

Fixes <http://bugs.gnu.org/17827>.

* guix/build/linux-initrd.scm (mount-root-file-system) [volatile-root?]:
  Pass unionfs '-o max_file=65536'.