Smaller GNOME stuff

IconText cell renderer for GTKmm 2.4: Works like the Text cell renderer, but can optionally contain an additional icon. Better than packing a Pixbuf and a Text cell renderer, because this way, empty icons don't take up any horizontal space.
Indenting cell renderer for GTKmm 2.4: This can be used to show trees in a TreeView without the expander/collapser arrows.
CustomEntry combo box for GTKmm 2.4: Works a lot like the standard Entry combo box, but you don't have to store strings in the underlying TreeModel, instead, you can convert on-the-fly via a callback.
GNOME Summaries in Hungarian