Use omniauth-browserid from callahad's fork
OmniAuthHelper is better name than OauthHelper

Conflicts:
	app/models/user.rb
	spec/models/user_spec.rb
Add login via Mozilla Persona
Extract base js assets bundle
Make Persona the only login option (with the ability to access old accounts)
Remove unnecessary test for user factory
Refactor User.for_credentials/for_email into class methods
Auto-focus nickname field on new user form
Don't override error message for user's nickname uniqueness
Improvements to the new sign in flow
Improve wording
Redirect to "getting started" page after sign up
Upgrade shoulda-matchers
Validate presence and uniqueness of both nickname and email
Auto-strip whitespace from email and nickname
Use auth token for permanent sessions
Add missing indexes
Improve the account settings page
Upgrade simple_form to 3.0.0
Don't take current user's email from current profile page's user