def set_status(message, percentage)
      return false unless have_lock?
      @stat_handle.rewind
      @stat_handle.truncate 0
      @stat_handle.write(message.to_s.strip + "\n")
      @stat_handle.write(percentage.to_s.strip + "\n")
      @stat_handle.flush
      true
    end
def set_status(message, percentage)
      return false unless have_lock?
      @stat_handle.rewind
      @stat_handle.truncate 0
      @stat_handle.write(message.to_s.strip + "\n")
      @stat_handle.write(percentage.to_s.strip + "\n")
      @stat_handle.flush
      true
    end
Sets the status message and progress if this instance has a lock on the status/lock file.

 Returns true after successfully setting the status.
 Returns false if this instance does not currently hold the lock.