new (cColormap)

    /*
     * Get the default X11 Colormap on the specified Display and screen.
     * Raises a RunTimeError exception if the colormap could not be
     * allocated.
     *
     * Note: This method is not available unless Imlib2-Ruby was compiled
     * with X11 support.  You can check the constant Imlib2::X11_SUPPORT to
     * see if X11 support is available.
     *
     * Examples:
     *   cmap = Imlib2::X11::Colormap.new display, screen_num
     *
     */
    VALUE cmap_new(VALUE klass, VALUE display, VALUE screen) {