minor variable rename
minor cleanup
we DO need to call .AllChildren instead of .Children.

otherwise "Notebook" widgets (like the one being used in GeoFinder)
will not properly get localized
again allow special characters in localization keys
to be able to distinguish them from other ones which are NEARLY the same but WITHOUT special characters
- changed the name "Label" of to "Title" because it is no Gtk Label (avoid confusion)
- pimped the UpdateTitle() function with localization (I need that change for the MapStyleEditor class)