Generate Sessions controller
Add remember_token to users
Comment on alternatives for attr_accessible
Include SessionsHelper
Define basic Sessions actions
Define methods to sign-in users, and query/set/get the current user
Add callback for creating a remember_token (incl. the method setting it)
Add links for sign-in/out and account (-> profile, settings) - based on signed-in status
Configure routes for signup, signin and signout paths
Add view for sessions#new