message: DOC: add more explanation for auxiliary_name_scope
diff: @@ -1778,6 +1778,23 @@ class variable_scope(object):
  assert v.name == "foo/bar/v:0"
  ```
  + Simple example of how to reenter a premade variable scope safely:
  +
  + ```python
  + with tf.variable_scope("foo") as vs:
  + pass
  +
  + # Re-enter the variable scope.
  + with tf.variable_scope(vs,
  + auxiliary_name_scope=False) as vs1:
  + # Restore the original name_scope.
  + with tf.name_scope(vs1.original_name_scope):
  + v = tf.get_variable("v", [1])
  + assert v.name == "foo/v:0"
  + c = tf.constant([1], name="c")
  + assert c.name == "foo/c:0"
  + ```
  +
  Basic example of sharing a variable AUTO_REUSE:
  ```python
  @@ -1915,7 +1932,9 @@ class variable_scope(object):
  (which must have the same shape). Constraints are not safe to
  use when doing asynchronous distributed training.
  auxiliary_name_scope: If `True`, we create an auxiliary name scope with
  - the scope. If `False`, we don't touch name scope.
  + the scope. If `False`, we don't create it. Note that the argument is
  + not inherited, and it only takes effect for once when creating. You
  + should only use it for re-entering a premade variable scope.
  Returns:
  A scope that can be captured and reused.
  