Get running under Play 2.2.

The example now runs under Play 2.2.

- Reorganized slightly to follow what appears to be Play 2.2 idiom as far as project structure goes.

- I'm only testing CAS authentication. The app correctly redirects to the CAS server, and then correctly validates the token.  However, errors occur from upstream after CAS redirects back to the application.  This appears to be induced by the changes in the Play results structure.

java.lang.NoSuchMethodError: org.pac4j.play.CallbackController.redirect(Ljava/lang/String;)Lplay/mvc/Result;

It may be possible to correct this by changing the way RequiresAuthentication is called here in the example code.