Convert common syndication parser library to a class

It would be great if the common syndication parser library was a class rather than a series of functions.

I am currently putting together a parser to ingest an RSS feed with some some custom fields. For the most part, the common syndication parser is exactly what I need, I just need to add the ability for it to parse these custom fields. It would be easier to extend the common syndication parser if it were OO rather than just a series of functions.

Otherwise, I really like the direction Feeds is heading in - it's much nicer to work with than FeedAPI! Thanks very much for the great work.