additional common.is_*_dtype tests in core.common
make better use of dtype tests in nanops
API: add/clarify numpy ufunc prepare/wrap
Remove unused variable assignment
Add notes deprecating in_ipnb and in_qtconsole
Merge pull request #7499 from takluyver/ipy-no-detect-frontend

Deprecate detection of IPython frontends
DOC: Add cookbook recipe like R's `expand.grid()`

Add `expand_grid()` recipe to cookbook

Add note about cookbook recipe to release notes

Revert "Add note about cookbook recipe to release notes"

This reverts commit e431a024c2e688f9917cafb12235ee72ecc3e119.

Remove pandas import, print dataframe in cookbook
Merge pull request #7556 from onesandzeroes/expand-grid

DOC: Cookbook recipe for emulating R's expand.grid() (#7426)
BUG/PERF: perf issues in object groupby aggregations (GH7555)
Merge pull request #7568 from jreback/perf2

BUG/PERF: perf issues in object groupby aggregations (GH7555)
TST: Remove else after except in tests for io.data.Options.

Made the old tests consistent with the new tests, also passed the RemoteDataError on skip.

CLN:  Moved test for no tables to the get_option_tables method.
Merge pull request #7564 from dstephens99/master

TST: Remove else after except in tests for io.data.Options.
Merge pull request #7547 from toddrjen/nanopsclean

Minor cleanups for nanops