gtkmm: New API in gtkmm 2.16

gtkmm 4.6.0

New API in gtkmm 2.16

Member Gtk::Builder::add_from_file (const std::string& filename, const char* object_id)
Member Gtk::Builder::add_from_string (const Glib::ustring& buffer, const char* object_id)
Member Gtk::Builder::create_from_file (const std::string& filename, const char* object_id)
Member Gtk::Builder::create_from_string (const Glib::ustring& buffer, const char* object_id)
Member Gtk::CellView::unset_model ()
Member Gtk::ComboBox::unset_model ()
Member Gtk::EntryCompletion::unset_model ()
Member Gtk::IconView::unset_model ()
Class Gtk::Orientable