*   Update gRPC release to 0.14.
*   Eigen version upgrade.
*   Switch to eigen thread pool
*   `tf.nn.moments()` now accepts a `shift` argument. Shifting by a good
    estimate of the mean improves numerical stability. Also changes the behavior
    of the `shift` argument to `tf.nn.sufficient_statistics()`.
*   Performance improvements
*   Many bugfixes
*   Many documentation fixes