Override for better log format

        Tornado format:
        [INFO 2015-03-24 11:29:57 app:521] 200 GET /static/css/lib/pure-min.css (127.0.0.1) 6.76ms
        Current format:
        [gevent.wsgi] INFO 127.0.0.1 - - [2015-03-24 11:18:45] "GET /test HTTP/1.1" 200 304 0.000793

def format_request(self):
        """Override for better log format

        Tornado format:
        [INFO 2015-03-24 11:29:57 app:521] 200 GET /static/css/lib/pure-min.css (127.0.0.1) 6.76ms
        Current format:
        [gevent.wsgi] INFO 127.0.0.1 - - [2015-03-24 11:18:45] "GET /test HTTP/1.1" 200 304 0.000793
        """
        fmt = '{now} {status} {requestline} ({client_address}) {response_length} {delta}ms'

        requestline = getattr(self, 'requestline')
        if requestline:
            # Original "GET / HTTP/1.1", remove the "HTTP/1.1"
            requestline = ' '.join(requestline.split(' ')[:-1])
        else:
            requestline = '???'

        if self.time_finish:
            delta = '%.2f' % ((self.time_finish - self.time_start) * 1000)
        else:
            delta = '-'

        data = dict(
            now=datetime.datetime.now().replace(microsecond=0),
            response_length=self.response_length or '-',
            client_address=self.client_address[0] if isinstance(self.client_address, tuple) else self.client_address,
            status=str(self._get_status_int()),
            requestline=requestline,
            delta=delta,
        )

        return fmt.format(**data)