Refactoring of rss feed parsing. rss does not use namespace, extension to rss spec use namespaces. Fixed rss parser to check fully qualified name so did not get confused by similar elements within different namespaces. Fixed bug where if uri did not contain feed, still tried to create a feed record and crashed.
Some exception handling around fetching a feed from a uri, if the request fails, eg 404 error, rather than throw exception just return null.
Fix bug in subscription code, check for user already subscribed to feed. Check feed already known, check feed data actually returned from uri lookup.