Forkparser

also, make sure we send the User-Agent even if urllib2 isn't available.
Match any variation of backend.userland.com/rss namespace.

2.3.1 - 6/12/2003 - MAP - if item has both link and guid, return both as-is.

2.2 - 1/27/2003 - MAP - added attribute support, admin:generatorAgent.
start_admingeneratoragent is an example of how to handle elements with
only attributes, no content.

useless. Fixes the problem JD was addressing by adding it.

because of etag/modified, return the old etag/modified to the caller to
indicate why nothing is being returned

JD - use inchannel to watch out for image and textinput elements which can
also contain title, link, and description elements
JD - check for isPermaLink='false' attribute on guid elements
JD - replaced openAnything with open_resource supporting ETag and
If-Modified-Since request headers
JD - parse now accepts etag, modified, agent, and referrer optional
arguments
JD - modified parse to return a dictionary instead of a tuple so that any
etag or modified information can be returned and cached by the caller