gtkmm: New API in gtkmm 2.36
- Member Gdk::Pixbuf::copy_options (const Glib::RefPtr< Pixbuf >& dest_pixbuf) const
- Member Gdk::Pixbuf::remove_option (const Glib::ustring& key)
- Member Gdk::PixbufFormat::is_save_option_supported (const Glib::ustring& option_key) const