*   Clarify that tensorflow::port::InitMain() *should* be called before
        using the TensorFlow library. Programs failing to do this are not
        portable to all platforms.
*   Deprecations and Symbol renames.
    *   Removing deprecations for the following endpoints: `tf.acos`,
        `tf.acosh`, `tf.add`, `tf.as_string`, `tf.asin`, `tf.asinh`, `tf.atan`,
        `tf.atan2`, `tf.atanh`, `tf.cos`, `tf.cosh`, `tf.equal`, `tf.exp`,