Added parameter to modify venerable app behavior.

[mibollma]

Additional optional parameter (-b) to modify the behavior regarding the venerable app.

• delete: Removes the venerable app after successful deployment. Default value for backward compatibility.
• stop: Stops the venerable app after successful deployment. Useful for running additional integration/system tests against the new app and rolling back in case of failure. Solves Option to choose between deleting and stopping old application #53.
• ignore: Does not change the venerable app after successful deployment. Similar to Created the keep-old-app flag #54.