0.6.1

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.