ScenarioManager CLI: support for old -w option

The old startScenario.sh sripts had a -w option. If set, the script waited until ctrl+c was pressed and then all applications were stopped. This was very useful for starting/stopping scenarios. A similar option for the ScenarioManager CLI would be nice.

At the moment I wrote a workaround bash script:

• run "armarx scenario start ."
• wait for ctrl+c
• run "armarx scenario stop ."

That works, but is not an elegant solution.