gnu: services: Add MATE desktop service.

* gnu/services/desktop.scm (<mate-desktop-configuration>,
mate-desktop-service-type): New variable.
(mate-desktop-service): New public variable.

* doc/guix.texi (Desktop Services): Document the service.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: mate: Add more packages.

* gnu/packages/mate.scm (mate)[inputs]: Add "mate-user-guide", "mate-calc", "mate-backgrounds",
"mate-netbook", "hicolor-icon-theme", "mate-utils", "engrampa", "eom", "mate-polkit",
"mate-system-monitor", "mate-utils", "pluma", "atril".

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-polkit.

* gnu/packages/mate.scm (mate-polkit): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-system-monitor.

* gnu/packages/mate.scm (mate-system-monitor): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add pluma.

* gnu/packages/mate.scm (pluma): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add engrampa.

* gnu/packages/mate.scm (engrampa): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add eom.

* gnu/packages/mate.scm (eom): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-utils.

* gnu/packages/mate.scm (mate-utils): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-screensaver.

* gnu/packages/mate.scm (mate-screensaver): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-netbook.

* gnu/packages/mate.scm (mate-netbook): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add libfakekey.

* gnu/packages/xdisorg.scm (libfakekey): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-icon-theme-faenza.

* gnu/packages/mate.scm (mate-icon-theme-faenza): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-common.

* gnu/packages/mate.scm (mate-common): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-backgrounds.

* gnu/packages/mate.scm (mate-backgrounds): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-calc.

* gnu/packages/mate.scm (mate-calc): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add atril.

* gnu/packages/mate.scm (atril): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: caja: Add native-search-paths.

* gnu/packages/mate.scm (caja)[native-search-paths]: Add it.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add caja-extensions.

* gnu/packages/mate.scm (caja-extensions): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: mate-session-manager: Configure with with elogind support.

* gnu/packages/mate.scm (mate-session-manager)[arguments]: Add '--enable-elogind'
to configure-flags.
(phases): Add 'pre-configure' phase.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu: Add mate-user-guide.

* gnu/packages/mate.scm (mate-user-guide): New variable.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>