Require login/authentication to use the single page app

With this PR, you will be required to login to use the app.

If your session expires while you are already in the app, you will be redirected to the login page after navigating (or triggering a REST call some other way).  After logging in, you will be redirected back to the page you were on or the page you were trying to navigate to.

Your email address is rendered in the top right. We could change that to First and Last name if you guys want.