Merge pull request #4641 from jreback/arthops

ENH: (GH4629) Support for using a DatetimeIndex/PeriodsIndex directly in a datelike calculation
FIX groupby apply ignores as_index
TST another groupby as_index test
ENH Factored out excel_value_to_python_value from ExcelFile::_parse_excel (GH4589)
ENH add bins argument to value_counts

ENH Series method accepts Categorical

Also, adds arguments present in top-level function to the Series
method (sort and ascending).
Merge branch 'excel_parse_utils' of https://github.com/cancan101/pandas into cancan101-excel_parse_utils

Conflicts:
	doc/source/release.rst
Merge pull request #4645 from jreback/hdf_api

API: remove the table keyword, replaced by fmt='s|t'
BUG: Fix boolean comparison with a DataFrame on the lhs, and a list/tuple on the rhs GH4576
Merge pull request #4585 from jreback/boolean_comp

BUG: Fix boolean comparison with a DataFrame on the lhs, and a list/tuple on the rhs GH4576
CLN/API: Refactor of _get_numeric_data/_get_bool_data to core/generic.py, allowing Series/Panel functionaility
CLN: cleaned up numeric dtype tests in tools/plotting.py
Merge pull request #4675 from jreback/numeric

CLN/API: Refactor of _get_numeric_data/_get_bool_data to core/generic.py, allowing Series/Panel functionaility
BUG: GH 4667 setitem error/dtype wrong with Series/Frame when setting with None
Merge pull request #4676 from jreback/where_none

BUG: GH 4667 setitem error/dtype wrong with Series/Frame when setting with None
BUG: (GH4626) Fix decoding based on a passed in non-default encoding in pd.read_stata
Merge pull request #4643 from jreback/stata_encode

BUG: (GH4626) Fix decoding based on a passed in non-default encoding in pd.read_stata
Added ind and bw_method kwargs to KdePlot
Merge pull request #4316 from khgitting/kde_kwargs

Added ind and bw_method kwargs to KdePlot
BUG: preserve empty dtype if possible when creating an empty BlockManager
Merge pull request #4677 from jreback/numeric2

BUG: preserve empty dtype if possible when creating an empty BlockManager