FIX raise when groupby selecting cols not in frame
PERF: dataframe.from_records: read into list w/ itertools.islice when specifying nrows #6700
StataWriter: Replace missing values in string columns by an empty string
BUG: bug in timedelta ops on 32-bit platforms (GH6808)
BUG/ENH: Fix to_excel representation of inf values
Merge pull request #6812 from jtratner/excel-inf

BUG/ENH: Fix to_excel representation of inf values
BUG/API: disallow boolean arithmetic operations
CLN/TST: move ops test from test_frame.py to test_expressions.py
BUG: check for dtype attr then check block types if no dtype attr
Merge pull request #6803 from cpcloud/bool-arith-ops-6762

BUG/API: disallow boolean arithmetic operations
Remove number of deprecated parameters/functions/classes [fix #6641]
ENH: added nunique and value_counts functions to Index
Merge pull request #6734 from sinhrks/ind_nunique

ENH: added nunique function to Index
BLD: spring cleaning on Makefile
Merge branch '6700_dataframe_from_records_itertools' of https://github.com/westurner/pandas into westurner-6700_dataframe_from_records_itertools

Conflicts:
	doc/source/release.rst
	vb_suite/frame_methods.py
TST: dtype fix for test_base, from PR 6734)
Merge pull request #6784 from cpcloud/clean-up-makefile

BLD: spring cleaning on Makefile
BUG: Fix unconverting of long strings from HDF (GH6166)
TST/BUG: make the gender variable non random in test_hist_by_no_extra_plots
CLN: leftover rebasing from 405018c