[gtkada] ANN: GtkAda contributions v2.10

[Dmitry A. Kazakov]

This version is compatible with the newest version 2.18 of GtkAda.

Further changes are:

- The procedure Set was added to the package Gtk.Handlers.References for
explicit unsetting references;
- The procedures Has_Tooltip, Set_Has_Tooltip, Set_Tip were added to
Gtk.Missed;
- Gtk.Handlers.Generic_Callback was added to support signal handlers with
return values handled as GValue;
- The package Gtk.Recent_Manager was renamed to Gtk.Recent_Manager_Alt to
keep it compatible to GtkAda 2.18.0. For earlier versions of GtkAda,
renaming packages are provided for backward compatibility;
- The Gtk.Object.Checked_Destroy procedure was added to safely destroy
floating widgets;
-The package Gtk.Recent_Manager_Keys now provides simplified means to store
and restore values by key, store and restore contents of combo boxes.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de