OpenID 2.0 spec violation - Normalize URL according to RFC3986 Section 6

The OpenID 2.0 specification mandates that we normalize user-supplied identifiers according to RFC3986.

Inspiration:
http://pear.php.net/package/Net_URL2/docs/latest/__filesource/fsource_Ne...
http://framework.zend.com/svn/framework/standard/trunk/library/Zend/Open...