Add feeds.py

This is a huge change. Feed parsing is now done in a separate file, much cleaner. The code of the lib tends to repeat itself a lot though. It should be possible to improve it. Code should be more stable.
Change morss.py to use feeds.py

No other changes should appear in this commit
Detect provided content with word count

This is instead of character count.
Better content insertion

Also takes care of description, by creating one, when missing.
Use ' instead of " when possible