Cancel the job. Returns 1 if job was cancelled.

def cancel(self):
        """Cancel the job. Returns 1 if job was cancelled."""
        if self.queue_id is None: return 0
        if self.status >= self.S_DONE: return 0

        exit_status = self.manager.cancel(self.queue_id)
        if exit_status != 0:
            logger.warning("manager.cancel returned exit_status: %s" % exit_status)
            return 0

        # Remove output files and reset the status.
        self.history.info("Job %s cancelled by user" % self.queue_id)
        self.reset()
        return 1