API change: ``Frame.from_element_loc_items()`` renamed ``Frame.from_element_items``; ``Frame.from_element_iloc_items`` is removed.
``Frame.assign`` now returns a ``FrameAssign`` instance with an ``apply`` method to permit using the assignment target, after function application, as the assignment value.
``Series.assign`` now returns a ``SeriesAssign`` instance with an ``apply`` method to permit using the assignment target, after function application, as the assignment value.
``IndexDatetime`` subclasses now properly assign ``name`` attrs from an `Index` given as an initializer.
``Series.items()`` now returns labels of ``IndexHierarchy`` as tuples instead of ``np.ndarray``.
Added ``Batch.apply_except`` and ``Batch.apply_items_except`` to permit ignore exceptions on function application to contained Frames.
Added ``Batch.unique()``.
``Batch`` now supports operations on ``Frame`` that return an ``np.ndarray``.
Added ``Quilt.from_items()`` and ``Quilt.from_frames()``.
``Bus.sort_index()`` and ``Bus.sort_values()`` now return a ``Bus`` instance.
Improvements to ``Bus.items()``, ``Bus.values`` for optimal ``Store`` reads when ``max_persist`` is None.
Implemented ``Bus.rename()`` to return a ``Bus`` instance.
Implemented ``Bus.drop[]`` to return a ``Bus`` instance.
Implemented ``Bus.reindex()``, ``Bus.relabel()``, ``Bus.relabel_flat()``, ``Bus.relabel_level_add()``, ``Bus.relabel_level_drop()``, ``Bus.rehierarch()``.
Implemented ``Bus.roll()``, ``Bus.shift()``.