Syndication feed auto-discovery

 Feed::Find implements feed auto-discovery for finding syndication
 feeds, given a URI. It (currently) passes all of the auto-discovery
 tests at http://diveintomark.org/tests/client/autodiscovery/.
 .
 Feed::Find will discover the following feed formats:
  * RSS 0.91
  * RSS 1.0
  * RSS 2.0
  * Atom