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