Add support for feeds with URLs that are in IDN format.

JFeed uses XMLReader to connect to and process feeds. XMLReader does not support IDN formated URIs.  Therefore when users of JFeed attempt to process IDN URIs they fail.  

This pull request solves this problem by adding support for an external library that can translate from and to IDN/UTF8 and  Puny Code which is the way that servers handle  these domains.

In addition to the library this adds 4 methods, 2 for each direction.  toPunycode and fromPunycode handle strings.  urlToPunycode and urlToUtf8 handle full uris be coping with the punctuation characters  and scheme.  

Use of these are shown in an example com_newsfeeds  where Puny Code urls are translated into IDN urls when displayed on the category list layout.