gtkIconFactoryAdd: gtkIconFactoryAdd
Description
Adds the given icon.set to the icon factory, under the name
stock.id. stock.id should be namespaced for your application,
e.g. "myapp-whatever-icon". Normally applications create a
GtkIconFactory, then add it to the list of default factories with
gtkIconFactoryAddDefault. Then they pass the stock.id to
widgets such as GtkImage to display the icon. Themes can provide
an icon with the same name (such as "myapp-whatever-icon") to
override your application's default icons. If an icon already
existed in factory for stock.id, it is unreferenced and replaced
with the new icon.set.Usage
gtkIconFactoryAdd(object, stock.id, icon.set)