ENH/DOC: Cleanup docstrings on NDFrame
micro + nanosecond time support
Merge pull request #4848 from TomAugspurger/isin_notes2

DOC: isin Example for .13 release notes
TST: allow to check for specific xlrd version and skip reader test if xlrd < 0.9
BF: import isnull
Merge pull request #5059 from neurodebian/bf-isnull

BF: import isnull
Merge pull request #3060 from wuan/nanosecond_time

ENH: support for nanosecond time in offset and period
API: allow single element boolean Series to mimic numpy behavior( related GH4657)

TST: test for single element with null-like

DOC: deprecation message for using bool(Series([True]))
CLN: add .bool() method for single length evaluation
API: provide __dir__ method (and local context) for tab completion / remove ipython completers code (GH4501)
Merge pull request #4738 from jreback/bool_single

API: allow single element boolean Series to improve on numpy behavior( related GH4657)
Merge pull request #5050 from jreback/dir

API: provide __dir__ method (and local context) for tab completion / remove ipython completers code
BUG: Bug in setting with ix/loc and a mixed int/string index (GH4544)
Merge pull request #5064 from jreback/ix_edge

BUG: Bug in setting with ix/loc and a mixed int/string index (GH4544)
Merge pull request #5052 from jtratner/update-docstrings-as-appropriate

ENH/DOC: Cleanup docstrings on NDFrame
BUG: Fix Index.__iadd__ bug by setting equal to __add__

fixes #4996

alias Index's __isub__ to __sub__

document fixes to #4996

index isub test

roll back everything non-iadd related
CLN: clean up tslib.pyx a bit
CLN: skip without np 1.7
Merge pull request #5067 from cpcloud/tslib-unreachable-fixups

CLN: remove unreachable code in tslib.pyx
BUG: Make sure series-series boolean comparions are label based (GH4947)