FIX raise when groupby selecting cols not in frame
ENH partial sorting for mi in sortlevel
DOC partial sort for multiindex
Add how kwarg to rolling_* functions [fix #6297]
API: remove the copy kw from .xs to prevent accidental / confusing setting (GH6894)
BUG: legend behaves inconsistently when plotting to the same axes repeatedly
Merge pull request #6919 from jreback/xs_copy

API: remove the copy kw from .xs to prevent an expectation of a view (which may not be possible)
Merge pull request #6845 from jsexauer/fix6297_pr

BUG/ENH: Add how kwarg to rolling_* functions [fix #6297]
Merge pull request #6678 from sinhrks/legend_pr

BUG: legend behaves inconsistently when plotting to the same axes
API: Stop modifying SQL column and names, and warn when pertinent.
BUG/INT: Internal tests for patching __finalize__ / bug in merge not finalizing (GH 6923)
Merge pull request #6924 from jreback/finalize

BUG/INT: Internal tests for patching __finalize__ / bug in merge not finalizing (GH6923)
Merge pull request #6902 from danielballan/remove-safe-col-names

API: Stop modifying SQL column and names, and warn when pertinent.
ENH: Added CustomBusinessMonth offset.
API: align Panel.shift API with generic
change pct_change back to a kwarg
Merge pull request #6928 from TomAugspurger/panel_shift_kwarg

API/DEPR: Match Panel.shift()'s signature to generic
Deprecate order kwarg in factorize
BUG/INT: Internal tests for patching __finalize__ / bug in concat not finalizing (GH 6927)
Merge pull request #6866 from bjonen/cbm

Custom Business Month