Allow cluster switch-over operation from Controller start script

Current Situation

• The Controller start script for Unix and Windows allows to start, stop, restart, abort and kill a Controller instance.
• However, there is no operation to switch-over to a standby Controller instance in a Controller Cluster. This operation is available from the JOC Cockpit and the REST API only.

Desired Behavior

• The Controller start script for Unix and Windows should allow the operation to switch-over to a standby instance.
  • controller.sh|.cmd switch-over
• This command has to be executed from the active Controller instance.
• This command will be denied when executed from a standby Controller instance.