Terminate the script.

def exit(self, status=EXIT_OK, message=None):
        """
        Terminate the script.
        """
        if not self.parser:
            self.parser = argparse.ArgumentParser()
        if self.msg_on_error_only:
            # if msg_on_error_only is True
            if status != EXIT_OK:
                # if we have an error we'll exit with the message also.
                self.parser.exit(status, message)
            else:
                # else we'll exit with the status ongly
                self.parser.exit(status, None)
        else:
            # else if msg_on_error_only is not True
            # we'll exit with the status and the message
            self.parser.exit(status, message)