gnu: Add perl-mailtools.

* gnu/packages/perl.scm (perl-mailtools): New variable.

gnu: Add perl-convert-binhex.

* gnu/packages/perl.scm (perl-convert-binhex): New variable.

gnu: Add perl-moox-late.

* gnu/packages/perl.scm (perl-moox-late): New variable.

gnu: Add perl-moox-handlesvia.

* gnu/packages/perl.scm (perl-moox-handlesvia): New variable.

gnu: Add perl-data-perl.

* gnu/packages/perl.scm (perl-data-perl): New variable.

gnu: Add perl-moox.

* gnu/packages/perl.scm (perl-moox): New variable.

gnu: texinfo: Add 6.5.

* gnu/packages/texinfo.scm (texinfo-latest): New variable.

gnu: youtube-dl: Update to 2017.09.11.

* gnu/packages/video.scm (youtube-dl): Update to 2017.09.11.

gnu: gtksourceview: Update to 3.24.4.

* gnu/packages/gtk.scm (gtksourceview): Update to 3.24.4.

gnu: libpeas: Update to 1.22.0.

* gnu/packages/gnome.scm (libpeas): Update to 1.22.0.
[inputs]: Remvoe libxml2.

gnu: network-manager: Update to 1.8.2.

* gnu/packages/gnome.scm (network-manager): Update to 1.8.2.

gnu: tracker: Update to 1.12.3.

* gnu/packages/gnome.scm (tracker): Update to 1.12.3.

gnu: gnome-shell-extensions: Update to 3.24.3.

* gnu/packages/gnome.scm (gnome-shell-extensions): Update to 3.24.3.

gnu: gnome-settings-daemon: Update to 3.24.3.

* gnu/packages/gnome.scm (gnome-settings-daemon): Update to 3.24.3.

gnu: gsettings-desktop-schemas: Update to 3.24.1.

* gnu/packages/gnome.scm (gsettings-desktop-schemas): Update to 3.24.1.

gnu: imagemagick: Update to 6.9.9-12.

* gnu/packages/imagemagick.scm (imagemagick): Update to 6.9.9-12.

gnu: libraw: Update to 0.18.4.

* gnu/packages/photo.scm (libraw): Update to 0.18.4.

gnu: ffmpeg: Update to 3.3.4.

* gnu/packages/video.scm (ffmpeg): Update to 3.3.4.

gnu: feh: Update to 2.20.

* gnu/packages/image-viewers.scm (feh): Update to 2.20.

gnu: notmuch: Update to 0.25.1.

* gnu/packages/mail.scm (notmuch): Update to 0.25.1.