Update to Play 2.1.1

I couldn't find a way to contact you (email?) so I send you this pull request.

The commit updates the requirements to Play 2.1.1 as specified in JavaMagazin 5/2013, but it doesn't seem to work as expected.

The credentials which should be stored in the Login class are null which makes the login impossible.

Maybe the error is related to the recent change to Form.form() ?

cheers
-Martin