gnu: gtk+: Update to 3.22.6.

* gnu/packages/gtk.scm (gtk+): Update to 3.22.6.

gnu: at-spi2-atk: Update to 2.22.0.

* gnu/packages/gtk.scm (at-spi2-atk): Update to 2.22.0.

gnu: at-spi2-core: Update to 2.22.0.

* gnu/packages/gtk.scm (at-spi2-core): Update to 2.22.0.

gnu: atk: Update to 2.22.0.

* gnu/packages/gtk.scm (atk): Update to 2.22.0.

gnu: gtksourceview: Update to 3.22.2.

* gnu/packages/gtk.scm (gtksourceview): Update to 3.22.2.

gnu: pango: Update to 1.40.3.

* gnu/packages/gtk.scm (pango): Update to 1.40.3.

gnu: harfbuzz: Update to 1.4.1.

* gnu/packages/gtk.scm (harfbuzz): Update to 1.4.1.

gnu: glib-networking: Update to 2.50.0.

* gnu/packages/gnome.scm (glib-networking): Update to 2.50.0.

gnu: python-pygobject: Update to 3.22.0.

* gnu/packages/glib.scm (python-pygobject): Update to 3.22.0.

gnu: gsettings-desktop-schemas: Update to 3.22.0.

* gnu/packages/gnome.scm (gsettings-desktop-schemas): Update to 3.22.0.

gnu: desktop-file-utils: Update to 0.23.

* gnu/packages/gnome.scm (desktop-file-utils): Update to 0.23.

gnu: shared-mime-info: Update to 1.8.

* gnu/packages/gnome.scm (shared-mime-info): Update to 1.8.

gnu: gmime: Update to 2.6.22.

* gnu/packages/mail.scm (gmime): Update to 2.6.22.

gnu: gdk-pixbuf: Eliminate graft.

* gnu/packages/gtk.scm (gdk-pixbuf): Update to 2.36.3.
[replacement]: Remove field.
(gdk-pixbuf/fixed): Remove variable.
(package/inherit): Remove macro.
(gdk-pixbuf+svg): Remove use of 'package/inherit'.

gnu: libgee: Update to 0.18.1.

* gnu/packages/gnome.scm (libgee): Update to 0.18.1.

gnu: vala: Update to 0.34.4.

* gnu/packages/gnome.scm (vala): Update to 0.34.4.

gnu: gobject-introspection: Update to 1.50.0.

* gnu/packages/glib.scm (gobject-introspection): Update to 1.50.0.

gnu: libgsf: Update to 1.14.41.

* gnu/packages/gnome.scm (libgsf): Update to 1.14.41.

gnu: dbus-glib: Update to 0.108.

* gnu/packages/glib.scm (dbus-glib): Update to 0.108.

gnu: libxml++: Update to 3.0.1.

* gnu/packages/gnome.scm (libxml++): Update to 3.0.1.