SimplePie 1.x

In order to make my caching and fetching scheme more efficient, I had a need to know whether a feed had changed. So what I was doing was taking an MD5 hash of the sanitised output storing it and comparing it. Two things would make this easier. The fetching scheme is to back off collection if the feed is changing much and fetch more frequently if it keeps changing.
1) Providing xml_dump as a string that can be queried rather than echoing it out as a web page. Somewhere around line 1778 set a public variable $this->clean_source = $data;
2) Expose something in the cacheing scheme to tell the program if the feed has changed.