Shutdown ECU-TEST.

Pipelines usage:
Signatures:
stopET(String toolName) : void
            
stopET(String toolName, int timeout) : void
            
ETInstance.stop() : void
            
ETInstance.stop(int timeout) : void
            
Examples:
stopET('ECU-TEST')
            
def instance = ET.installation('ECU-TEST')
stopET installation: instance.installation
            
def instance = ET.newInstallation('ECU-TEST', 'C:\\Program Files\\ECU-TEST 8.0')
instance.stop()