gnu: Add trio.

* gnu/packages/code.scm (trio): New variable.

gnu: ruby-ffi: Update to 1.9.14.

* gnu/packages/ruby.scm (ruby-ffi): Update to 1.9.14.

gnu: ruby-nokogiri: Update to 1.6.8.

* gnu/packages/ruby.scm (ruby-nokogiri): Update to 1.6.8.
[arguments]: Remove 'update-dependency' phase.  Add 'patch-extconf' phase.
[native-inputs]: Remove ruby-rake-compiler.
[propagated-inputs]: Add ruby-pkg-config.

gnu: Add ruby-pkg-config.

* gnu/packages/ruby.scm (ruby-pkg-config): New variable.

gnu: openssh: Add dependency on xauth.

Partly fixes <http://bugs.gnu.org/23317>.
Reported by Danny Milosavljevic <dannym@scratchpost.org>.

* gnu/packages/ssh.scm (openssh)[inputs]: Add XAUTH.

gnu: linux-libre@4.1: Update to 4.1.29.

* gnu/packages/linux.scm (linux-libre-4.1): Update to 4.1.29.

gnu: Add libgnomekbd.

* gnu/packages/gnome.scm (libgnomekbd): New variable.

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

gnu: Add s6-linux-utils.

* gnu/packages/skarnet.scm (s6-linux-utils): New variable.

Signed-off-by: Eric Le Bihan <eric.le.bihan.dev@free.fr>
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add s6-portable-utils.

* gnu/packages/skarnet.scm (s6-portable-utils): New variable.

Signed-off-by: Eric Le Bihan <eric.le.bihan.dev@free.fr>
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add s6-rc.

* gnu/packages/skarnet.scm (s6-rc): New variable.

Signed-off-by: Eric Le Bihan <eric.le.bihan.dev@free.fr>
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu: units: Update to 2.13.

* gnu/packages/maths.scm (units): Update to 2.13.

gnu: Add Go 1.6.

* gnu/packages/golang.scm (go-1.6): New variable.

Co-authored-by: Efraim Flashner <efraim@flashner.co.il>
Co-authored-by: Andy Wingo <wingo@igalia.com>
Co-authored-by: Ludovic Courtès <ludo@gnu.org>

gnu: imagemagick: Update to 6.9.5-4 [fixes CVE-2016-6491].

* gnu/packages/imagemagick.scm (imagemagick): Update to 6.9.5-4.

gnu: openttd: Update to 1.6.1.

* gnu/packages/games.scm (openttd): Update to 1.6.1 and expand the
package description.

Signed-off-by: Andreas Enge <andreas@enge.fr>

gnu: mutt: Update to 1.6.2.

* gnu/packages/mail.scm(mutt): Update to 1.6.2.

gnu: Add python-pygame.

* gnu/packages/game-development.scm (python-pygame): New variable.

gnu: Add libsmpeg.

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

emacs: Disable grafts when dry-run is enabled.

* emacs/guix-main.scm (process-package-actions): Set grafting according
to 'dry-run?'.
* guix/scripts.scm (build-package): Disable grafts when 'dry-run?' is #t.

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

gnu: stellarium: Improve description.

Suggested by Danny Milosavljevic <dannym@scratchpost.org>.

* gnu/packages/education.scm (stellarium)[description]: Mention telescope
tracking.

gnu: diamond: Update to 0.8.17.

* gnu/packages/bioinformatics.scm (diamond): Update to 0.8.17.