gnu: Add modem-manager.

* gnu/packages/freedesktop.scm (modem-manager): New variable.

gnu: Add libqmi.

* gnu/packages/freedesktop.scm (libqmi): New variable.

gnu: Add libmbim.

* gnu/packages/freedesktop.scm (libmbim): New variable.

gnu: wayland: Update to 1.9.0.

* gnu/packages/freedesktop.scm (wayland): Update to 1.9.0.

gnu: udisks: Separate HTML documentation.

* gnu/packages/freedesktop.scm (udisks)[outputs]: New field.
  [arguments]: Pass the --with-html-dir configure flag.

gnu: udisks: Mount things under /media.

* gnu/packages/freedesktop.scm (udisks)[arguments]: Add
  --enable-fhs-media.

gnu: udisks: Find the 'mount' command.

* gnu/packages/freedesktop.scm (udisks)[inputs]: Add UTIL-LINUX.
  [arguments]: Add 'set-mount-file-name' phase.

Merge branch 'dbus-update'

Merge branch 'master' into dbus-update

gnu: elogind: Provide the file name of 'halt' and 'reboot'.

* gnu/packages/freedesktop.scm (elogind)[inputs]: Add DMD.

gnu: elogind: Fix build by explicitly link with librt.

* gnu/packages/freedesktop.scm (elogind)[arguments]: Pass
  'LDFLAGS=-lrt' to configure.

Merge branch 'master' into core-updates

gnu: elogind: Update to version 219.12.

* gnu/packages/freedesktop.scm (elogind): Update to 219.12.  Use a tarball
  instead of a git checkout.

gnu: Add accountsservice.

* gnu/packages/freedesktop.scm (accountsservice): New variable.

gnu: libinput: Update to 0.21.0.

* gnu/packages/freedesktop.scm (libinput): Update to 0.21.0.

gnu: Add udisks.

* gnu/packages/freedesktop.scm (udisks): New variable.

gnu: Add libatasmart.

* gnu/packages/freedesktop.scm (libatasmart): New variable.

Merge branch 'master' into core-updates

gnu packages: Clean up synopses and descriptions.

* gnu/packages/admin.scm, gnu/packages/algebra.scm, gnu/packages/audio.scm,
  gnu/packages/backup.scm, gnu/packages/base.scm, gnu/packages/bittorrent.scm,
  gnu/packages/code.scm, gnu/packages/compression.scm,
  gnu/packages/databases.scm, gnu/packages/enchant.scm,
  gnu/packages/firmware.scm, gnu/packages/fonts.scm,
  gnu/packages/freedesktop.scm, gnu/packages/games.scm, gnu/packages/gd.scm,
  gnu/packages/gl.scm, gnu/packages/gnome.scm, gnu/packages/gsasl.scm,
  gnu/packages/gstreamer.scm, gnu/packages/gtk.scm, gnu/packages/guile.scm,
  gnu/packages/haskell.scm, gnu/packages/language.scm,
  gnu/packages/lesstif.scm, gnu/packages/libreoffice.scm,
  gnu/packages/linux.scm, gnu/packages/llvm.scm, gnu/packages/maths.scm,
  gnu/packages/mcrypt.scm, gnu/packages/mit-krb5.scm, gnu/packages/mp3.scm,
  gnu/packages/ncdu.scm, gnu/packages/networking.scm, gnu/packages/ntp.scm,
  gnu/packages/ocaml.scm, gnu/packages/openbox.scm, gnu/packages/pdf.scm,
  gnu/packages/perl.scm, gnu/packages/pretty-print.scm,
  gnu/packages/pulseaudio.scm, gnu/packages/python.scm,
  gnu/packages/rdesktop.scm, gnu/packages/rdf.scm, gnu/packages/ruby.scm,
  gnu/packages/slang.scm, gnu/packages/slim.scm, gnu/packages/telephony.scm,
  gnu/packages/tls.scm, gnu/packages/tmux.scm, gnu/packages/tre.scm,
  gnu/packages/unrtf.scm, gnu/packages/version-control.scm,
  gnu/packages/vpn.scm, gnu/packages/web.scm, gnu/packages/wget.scm,
  gnu/packages/xdisorg.scm, gnu/packages/xfce.scm, gnu/packages/xiph.scm:
  Fix typos.  Trim long lines.  Add missing periods in the end of sentences.
  Use double spaces between sentences.  Remove trailing whitespaces.

gnu: Add exempi.

* gnu/packages/freedesktop.scm (exempi): New variable.