Breaks Arabic (and presumably other unicode) filenames

Hi,

The plugin has not been tested with Arabic filenames. The plugin uses the WordPress core function sanitize_title() to translate the filenames into clean filenames. I will try to dig a little deeper and maybe complement this function with some more code that better handles Arabic and other unicode characters.

In case it helps, here is the function I ultimately created that solves my particular problem (that my RSS feed is invalidated if I have a “URL” property that includes Unicode symbols in the filename):

function gv_rawurlencode_url_filename($url) {
	/**
	 * Extract only the filename from the URL (encoding other parts messes up URL structure)
	 */
	$url_parts = parse_url($url);
	$url_pathinfo = pathinfo($url_parts['path']);
	$url_filename = $url_pathinfo['filename'];

	/**
	 * Encode the filename to avoid Unicode errors
	 */
	$filtered_filename = rawurlencode($url_filename);

	/**
	 * If encoding changed the filename repace it in the $url
	 */
	if ($url_filename !== $filtered_filename) :
		$url = str_replace($url_filename, $filtered_filename, $url);
	endif;

	return $url;
}