I've posted to GitHub a PHP class that I've written which can handle URL normalization, as specified by RFC 3986.

https://github.com/glenscott/url-normalizer

Specifically, the following normalization steps are performed:

1. Normalize case
2. Decode unreserved characters
3. Remove dot segments

An example of use:

require_once 'URLNormalizer.php';

$url = 'eXAMPLE://a/./b/../b/%63/%7bfoo%7d';
$un = new URLNormalizer();
$un->setUrl( $url );
echo $un->normalize();

// result: "example://a/b/c/%7Bfoo%7D"