A StockItem is a resource that is know throughout Gtk.
Defining you own Graphics.UI.Gtk.General.IconFactory.IconSets
as StockItems will make it possible for Gtk to choose the most
appropriate sizes and enables themes to override your built in
icons. A couple of constants are defined here as well. They are
useful in accessing Gtk's predefined items.
Retrieve a list of all known stock identifiers. These can either be
added by stockAddItem or by adding items to a
Graphics.UI.Gtk.General.IconFactory.IconFactory.
The list is sorted alphabetically (sorting is not Unicode aware).