ToolItem: Remove set/get_use_drag_window().
ToolItem: Remove set/get_use_drag_window().

Because it was removed from the GTK+ API:
https://git.gnome.org/browse/gtk+/commit/gtk/gtktoolitem.h?id=d9d0c56eb72cc433e21bf067fd8059f16e09b2a9

GNOME/gtkmm,GNOME/gtkmm,GNOME/gtkmm,GNOME/gtkmm