Use one single urllib2 handler

Makes feedify on html pages more powerful
Fix decoding

Was dropped in previous commit by mistake
Add support for JSON APIs in feedify
Add support for facebook API

Still lacks a mechanism to fetch "extended tokens", so for now, it's somehow useless
Improve facebook and feedburner workarounds
Don't fill facebook for now
Remove delItems setItems in feeds.py

That part is actually done in the FeedList class