Log Message:
gtkmm3: update to 3.22.2.

3.22.2 (stable):

Gtk:
* Editable, RecentChooser, Scale: Fix memory leaks.
  (Kjell Ahlstedt) Bug #783360
* PrintJob: Fix a call to Glib::throw_exception().
  (Kjell Ahlstedt)

Documentation:
* Gdk::RGBA: Update ctor(ustring) docs from GTK+
  (Daniel Boles) Bug #784483

3.22.1 (stable):

Unusually for a stable micro release, this release has some deprecations
compared to 3.22.0, to match similar deprecations in GTK+ 3.22.x.

Gtk:
* Container: Deprecate the child property.
  The underlying C property was deprecated in GTK+ 3.22.2.
  (Kjell Ahlstedt) Bug #773642.
* FileChooserDialog: Deprecate the constructors that take a backend
  parameter.
  (Kjell Ahlstedt)
* Menu: Deprecate popup().
  The underlying C functions were deprecated in GTK+ 3.22.2.
  (Kjell Ahlstedt) Bug #773642
* Widget:
  - Deprecate is_composited() and signal_composited_changed().
    The underlying C functions were deprecated in GTK+ 3.22.3.
  - Deprecate drag_dest_set_proxy().
    The underlying C functions was deprecated in GTK+ 3.22.3.
  (Kjell Ahlstedt) Bug #773642.
* Window: Deprecate set_wmclass().
  The underlying C functions was deprecated in GTK+ 3.22.2.
  (Kjell Ahlstedt) Bug #773642.

Gdk:
* Screen: Deprecate get_number(), get_width(), get_height(), get_width_mm(),
  get_height_mm(), make_display_name(), get_n_monitors(), get_primary_monitor(),
  get_monitor_geometry(), get_monitor_workarea(), get_monitor_at_point(),
  get_monitor_at_window(), get_monitor_width_mm(), get_monitor_height_mm(),
  get_monitor_plug_name(), get_monitor_scale_factor(), get_active_window().
  The underlying C functions were deprecated in GTK+ 3.22.2.
  (Kjell Ahlstedt) Bug #773642
* Visual: Deprecate get_system(), get_best(), get_best_depth(), get_best_type().
  The underlying C functions were deprecated in GTK+ 3.22.3.
  (Kjell Ahlstedt) Bug #773642
* Window:
  - Deprecate process[_all]_updates().
    The underlying C functions were deprecated in GTK+ 3.22.7.
  - Deprecate set_background(), get_background_pattern(), set_debug_updates().
    The underlying C functions were deprecated in GTK+ 3.22.2.
  (Kjell Ahlstedt)

Documentation:
* Box: Correct the constructor documentation.
  (Daniel Boles)
* CellLayout: Improve docs of get_first_cell() funcs
  (Daniel Boles)
* Frame: Fix the documentation of set_label_align().
  (Daniel Boles) Bug #774249
* Label: Improve h/valign constructor documentation and
  the improve the parameter names.
  (Daniel Boles) Bug #774652
* TreeModel: Improve docs of foreach*() functions
  (Daniel Boles)
* Minor cleanup of examples and demos.
  (Daniel Boles)
* demo: Don't call Notebook::remove_page() with invalid index.
  (Daniel Boles)

Build:
* Update the Visual Studio builds.
  (Chun-wei Fan)
* GtkMainConnectionNode: Remove unused method.
  (Kjell Ahlstedt)