Ben work

Kai - see my commit messages. I have a summary below:

-Added a few helpers, one of which can parse tags (still need to parse datetime stuff - we should look into jQuery pop up calendars here)
-User can now submit talks and tags (excepting datetime)
-Users can now view other users' profile pages (which at this point just includes their talks)
-Ordered all talks by created_at descending

TO DO:

-Wrap up all datetime stuff
-Add edit talk and delete talk functionality (and also order posts such that if a user modifies a talk, that talk moves to the front on the home page - so far it's just ordered by created_at)
-Sign in / sign out dynamic views
-More CSS stuff