Refactor CommentsController
Merge pull request #240 from joneslee85/refactor-feeds-controller

Refactor CommentsController
Combined comment scope
Starting on Google authentication
self_from_omniauth
Basic google omniauth working
An account link model is more useful here

If we correlate a user with a single service, then
existing users would be unable to use the new feature
without replacing their acconut.
Reproduce password validation defaults

oauth-based users won't need passwords
Switch to database session storage
Handle google/non-google email conflict
Confirmation prompt for creating new account
Fix the actual login bit and test it
Move settings spec out and update syntax
Refactor change password spec
All done except linking existing accounts
Linking done, now for unlinking
Unlinking from Google
Make google settings look sensible
Proper Google signin/signup buttons
Make confirm screen nicer