message: Update pydoc for several tfdbg hooks
  For classes:
  Specify that tfdbg.LocalCLIDebugHook can be used to debug instances
  of tf.estimator.Estimator. Remove mentions of
  tf.contrib.learn.Estimator and tf.contrib.learn.Experiment, as
  they are deprecated.
  For __init__ method of LocalCLIDebugHook:
  Clarify purpose of ui_type argument.
diff: @@ -31,15 +31,18 @@ from tensorflow.python.training import session_run_hook
  class LocalCLIDebugHook(session_run_hook.SessionRunHook):
  """Command-line-interface debugger hook.
  - Can be used as a monitor/hook for `tf.train.MonitoredSession`s and
  - `tf.contrib.learn`'s `Estimator`s and `Experiment`s.
  + Can be used as a hook for `tf.train.MonitoredSession`s and
  + `tf.estimator.Estimator`s. Provides a substitute for
  + `tfdbg.LocalCLIDebugWrapperSession` in cases where the session is not directly
  + available.
  """
  def __init__(self, ui_type="curses", dump_root=None, thread_name_filter=None):
  """Create a local debugger command-line interface (CLI) hook.
  Args:
  - ui_type: (str) user-interface type.
  + ui_type: (`str`) requested user-interface type. Currently supported:
  + (curses | readline).
  dump_root: (`str`) optional path to the dump root directory. Must be a
  directory that does not exist or an empty directory. If the directory
  does not exist, it will be created by the debugger core during debug
  @@ -153,8 +156,8 @@ class LocalCLIDebugHook(session_run_hook.SessionRunHook):
  class DumpingDebugHook(session_run_hook.SessionRunHook):
  """A debugger hook that dumps debug data to filesystem.
  - Can be used as a monitor/hook for `tf.train.MonitoredSession`s and
  - `tf.contrib.learn`'s `Estimator`s and `Experiment`s.
  + Can be used as a hook for `tf.train.MonitoredSession`s and
  + `tf.estimator.Estimator`s.
  """
  def __init__(self,
  @@ -229,8 +232,8 @@ class GrpcDebugHook(session_run_hook.SessionRunHook):
  When the arguments of debug_utils.watch_graph changes, strongly consider
  changing arguments here too so that features are available to tflearn users.
  - Can be used as a monitor/hook for `tf.train.MonitoredSession`s and
  - `tf.contrib.learn`'s `Estimator`s and `Experiment`s.
  + Can be used as a hook for `tf.train.MonitoredSession`s and
  + `tf.estimator.Estimator`s.
  """
  def __init__(self,
  