*[fix][#33478]Validating unicode url Feeds (RSS and Atom)

Tracker http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=33478&start=0

To test feed validation, enable Unicode Aliases in Global Configuration, create a menu item linking to a content category. Aliases should contain non-ASCII characters for both the menu and articles. Using simple accented letters will be enough.

Display the feed obtained and check the source (unicode characters should display percentencoded), try Validating.

This PR is a first shot at it.