Send statsd timing metrics in milliseconds

I was excited to see that gunicorn includes statsd reporting now, but I noticed that the times for request duration seemed quite low, and then noticed that it's sending times in seconds instead of milliseconds.

The statsd documentation indicates that timing values are expected to be in milliseconds:

  "The glork took 320ms to complete this time"
  https://github.com/etsy/statsd/blob/master/docs/metric_types.md#timing

I also confirmed that the Python statsd package is sending timing values in ms instead of s:

  https://github.com/jsocol/pystatsd/blob/master/statsd/client.py#L30-L31