2.91.2 (unstable):

Gdk:
* Added RGBA class.
* Display: Added set/unset_device_hooks().
* IconInfo: load_icon_symbolic(): Change the parameters from
	Color to RGBA.

Gtk:
* AboutDialog: Add activate_link signal.
* Application: Several methods removed.
* Entry:
  - Removed get_text_window() and get_icon_window().
  - Added get_text_area() and get_icon_area().
* CellView: Added set_background_rgba().
	* tools/m4/convert_gdk.m4: Added necessary conversion.
* ColorButton: Added a constructor taking a Gdk::RGBA, and
	get/set_rgba().
* ComboBoxText: Add remove_all(), replacing clear_items().
* LinkButton: Add activate_link signal.
* RecentInfo: Add get_gicon().
* Added Scrollable interface.
* IconView, Layout, TextView, ToolPallete, TreeView, ViewPort:
  Derive from Scrollable, removing their get/set/unset_h/vadjustment() methods
  and set_scroll_adjustments signals, because they are now in the base Scrollable.
* Widget:
  - Added queue_draw_region(), set/get_hexpand(),
	set/get_hexpand_set(), set/get_vexpand(), set/get_vexpand_set(),
	queue_compute_expand(), compute_expand(), shape_combine_region(),
	input_shape_combine_region()
  - Removed hide_all().

2.91.1.1 (unstable):