Fix start and stop scripts for Play 2.2.0

The dist task of Play 2.2.0 no longer creates target/start, instead it creates a script in target/universal/stage/bin. Also it puts the RUNNING_PID file in target/universal/stage when the generated script is used to start the app.

This patch fixes the script generation to work with Play 2.2.0, but does not address backward compatibility.
Bump up version number.
Updated README file.