Static-frame

Fixed issue in ``Frame.assign`` when assigning iterables into a single column.

Improvements to ``Frame.assign`` to handle unordered column selectors and preserve columnar types not affected by assignment.

Restored application of default column and index formattng in ``StoreXLSX``.

Fixed issue in ``__slots__`` usage of derived Containers.

Implemented ``StoreConfig`` and ``StoreConfigMap`` classes, and updated all ``Store`` and ``Bus`` interfaces to use them.

Implemented tracking of Store file modification times, and implemented raising exceptions for any unexpected file modifications.

Improved handling of reading XLSX files with trailing all-empty rows resulting from style formatting across empty data.

Improved HDF5 reading so as to reduce memory overhead.

Fixed issue in ``Frame.sort_values()`` when ``axis=0`` and underlying block structure is homogenous.

Improved performance of ``Frame.iter_group`` and related methods.

Fixed issue raised when calling built-in ``help()`` on SF containers.

Improved passing of index ``names`` in ``IndexHierarchy.to_pandas``.

Improved propagation of ``name`` in methods of ``Index`` and ``IndexHierarchy``.

StoreFilter`` added to the public namespace.

``names`` argument added to ``Frame.unset_index``.

Improved handling of ``ILoc`` usage within ``loc`` calls.

Improved input and output from/to XLSX.

Frame.from_concat``, ``Series.from_concat`` now accept empty iterables.

``Frame.iter_group.apply`` and related routines now handle producing a `Series` from a multi-column group selection.