Static-frame

Reimplemented ``Frame.to_npz()``, ``Frame.from_npz()``, removing support for object arrays (and pickles) and improving performance.

Added ``Bus.to_zip_npz()``, ``Bus.from_zip_npz()``, ``Quilt.to_zip_npz()``, ``Quilt.from_zip_npz()``, ``Batch.to_zip_npz()``, ``Batch.from_zip_npz()`` and ``Yarn.to_zip_npz()``.

Implemented ``Series.fillfalsy_forward()``, ``Series.fillfalsy_backward()``, ``Series.fillfalsy_leading()``, ``Series.fillfalsy_trailing()``.

Implemented ``Frame.fillfalsy_forward()``, ``Frame.fillfalsy_backward()``, ``Frame.fillfalsy_leading()``, ``Frame.fillfalsy_trailing()``.

Added ``Quilt.equals()``.

``Frame.from_pandas()`` now supports zero-sized DataFrame.

Fixed issue in ``Frame.set_index()`` where ``column`` is passed as ``None``.

Removed ``TypeBlocks._block_slices``.

Frame.to_pandas()`` now creates ``pd.RangeIndex`` for ``IndexAutoFactory``-created indices.

Performance enhancements to ``Frame.from_concat()``.

Corrected issue extracting containers stored in ``Series``.

Improved dtype resolution on ``Frame`` methods that reduce dimensionality.

Corrected issue where summing a ``Frame`` of Booleans along axis 0 resulted in Booleans instead of integers.

Performance enhancements to ``Frame.iter_group()`` and ``Frame.iter_group_items()``.