message: Clarifies py_func docs about copy/reference behavior in input args.
diff: @@ -163,6 +163,12 @@ def py_func(func, inp, Tout, stateful=True, name=None):
  having element types that match the corresponding `tf.Tensor` objects
  in `inp`, and returns a list of `ndarray` objects (or a single `ndarray`)
  having element types that match the corresponding values in `Tout`.
  + Important Note: Input and output numpy `ndarray`s of `func` are not
  + guaranteed to be copies. In some cases their underlying memory will be
  + shared with the corresponding TensorFlow tensors.
  + In-place modification or storing `func` input or return values in
  + python datastructures without explicit (np.)copy
  + can have non-deterministic consequences.
  inp: A list of `Tensor` objects.
  Tout: A list or tuple of tensorflow data types or a single tensorflow data
  type if there is only one, indicating what `func` returns.
  