code: public static void logShutdown(final Logger logger, final long endTime)
  	{
  		logger.logMessage(Level.INFO,
  				"DiffTool initiates SHUTDOWN\t" + Time.toClock(endTime));
  	}
docs: Logs the shutdown of the logger.
  
  @param logger
  reference to the logger
  @param endTime
  time since start