bsocial-comments tweaks/fixes

- Added moderator functionality to flag notifications
	- This is in addition to the existing author notification that was already present.
- Also includes a small fix for feedback urls so that they work with user_id as a GET var in addition to the object method that we moved to for the AJAX stuff.  
	- This keeps them working even if the user skips the ajax and clicks the link.


https://github.com/GigaOM/gigaom/issues/5448