The ``bloc`` and ``assign.bloc`` selectors on ``Frame`` now use ``[]`` instead of ``()``, aligning the interface with other selectors.
Added ``IndexNanosecond`` and ``IndexNanosecondGO`` indices.
All ``iter_*`` interfaces now explictly define arguments.
``Frame.fillna()`` and ``Series.fillna()`` now accept ``Frame`` and ``Series``, respectively, as arguments.
``Series.sort_index``, ``Series.sort_values``, ``Frame.sort_index``, ``Frame.sort_columns``, and ``Frame.sort_values`` now retain index/columns name after sorting.
Renamed ``Series.iter_group_index()``, ``Series.iter_group_index_items()``, ``Frame.iter_group_index()``, ``Frame.iter_group_index_items()`` to ``Series.iter_group_labels()``, ``Series.iter_group_labels_items()``, ``Frame.iter_group_labels()``, ``Frame.iter_group_labels_items()``
Fixed issue in ``Frame`` display where, when at or one less than the count of ``display_rows``, would display different numbers of rows for the ``Index`` and the body of the ``Frame``.
Zero-sized ``Frame`` now return zero-sized ``Series`` from selection where possible.