BUG: Fix for DateOffset's reprs. (GH4638)
BUG: wrong index name during read_csv if using usecols

Closes #4201

If user passes usecols and not names, then ensure that the
inferred names refer to the used columns, not the document's
columns.
Merge pull request #4868 from cancan101/offset_repr

BUG: Fix for DateOffset's reprs. (GH4638)
ENH Change ExcelFile and read_excel to accept a workbook for the io
(formerly path_or_buf) argument; this requires engine to be set.
(GH4961)
Merge pull request #4962 from cancan101/excel_take_workbook

ENH Change ExcelFile to accept a workbook for the path_or_buf argument.
BLD: numexpr 2.2.2 fixes incompatiblity in PyTables 2.4 (GH4908)

DOC: removes incompat warning
Merge branch 'issue-4201-index-name-wrong' of https://github.com/guyrt/pandas into guyrt-issue-4201-index-name-wrong

Conflicts:
	doc/source/release.rst
BUG: allow Timestamp comparisons on the left

Now tested with Series and DataFrame
BUG: Fix Timestamp compares to NaT

For example

    Timestamp('now') > pd.NaT

should return the same result as

    pd.NaT < Timestamp('now')

but before this commit it didn't because when Timestamp was on the left, the
values were compared whereas if NaT is on the left then the truth values are
hard-coded based on rules like NaN.
PERF: add vbench for DatetimeIndex unions/intersetions
PERF: add Timestamp <-> Series comparison vbench
Merge pull request #4983 from cpcloud/series-timestamp-compare

BUG: allow Timestamp comparisons on the left
API: add whitelist for methods that make sense GroupBy objects
Merge pull request #4887 from cpcloud/groupby-blacklist

API: disable to_csv and friends on GroupBy objects
ENH: evaluate datetime ops in python space with eval
TST: test nondate vs. date comparisons in query
TST: add test for multiindex resolver naming
ENH: convert all datetime-like objects to Timestamp
CLN: move resolvers getter to generic.py
PERF: add vbench for datetime comparisons