Merge pull request #23 from xiatao123/master

maintain both list and hash in user stories
Merge pull request #24 from xiatao123/master

reverse user story list order
Add categorization flag and make end to end working.
Sort by pubDate before sent to Client to do another sort by Score. NOTE: sort by ID is different from by pubDate. Not sure why.
fixed issue to update user_stories for all users