index.html: show sign in and sign up when we arent logged in -- show sign out when we are
signin.html: use spaces around a databinder
signout.html: sign a user out as soon as the page loads
signup.html: use spaces around a databinder
js/lifelog.js: fix loggedIn to camelcase
js/lifelog.js: rename signinctrl to authctrl
js/lifelog.js: support user logout
js/lifelog.js: remove controller for the main page