More flexible xml caching

New includes a 'type' var, to remember what we did out of it (normal, nothing, grabbed xml link, etc). xml/html mimetype are now saved in a dict, for easier editing, and consistency.
Add feedify, and use it in morss
Add support for twitter

Grabs "feed" from the html page, clips tweet and article together.
Twitter: use pahe <title> as feed title