ENH: Add `isin` method to DataFrame.

docs. to be rebased

ENH: Add isin method to DataFrame

Basic tests.

Added method and fixed tests.

ENH: Add ordered argument to df.isin()

Expects a sequence of arrays.

Updated release notes for df.isin()

CLN: cleanup

going to remove ordered argument.

Using a dict for ordered matching. Docs

BUG: fixed subselection length check issues.

Updated release notes for df.isin()

remove merge conflict note
ENH tweak DataFrame isin method
ENH add iloc argument to DataFrame isin
RLS: set released to True, edit release dates
RLS: edit windows note about numpy build version
Merge pull request #4258 from hayd/dataframe_isin2

ENH: Dataframe isin2
DOC/CLN move isin to 0.13 release note
DOC: add v0.13.0.txt to the index.rst (closes GH4288)
ENH/CLN: refactor of common code from frame/panel to generic.py
         axis creation routines now commonized under _setup_axes

ENH: more methods added

PERF: was missing multi-take opportunity in reindex
      was incorrectly passing to com._count_not_none
      doing an extra copy in certain cases

BUG: reindex with called with no args will by default return a copy (fixed bug)

ENH: moved filter and added axis arg
     moved where,mask,align

TST: make reindex benchmarks longer

CLN: fixed up names for creation in panelnd.py

DOC: minor release notes changes

ENH: initial commite - attempt to reengineer series to inherit from NDFrame rather than ndarray

ENH: fixed SparseDataFrame constructor with scalar values
     reindex still broken
     removed refs to SparseSeries in internals (not all SparseArray)

TST: more fixed

TST: more fixes

TST: more tests

TST: fixed up indexing

TST: more sparse fixes

BUG: reindex with single block manager now correctly fills with a method

BUG: fixed pickle I think

BUG: fixed set in internals for sparse

fixed boolean indexing iin series I thnk

BUG: fixed printing and inclusion of sparse series in DataFrame (now keeps its type),
     converted to dense for printing

CLN: took out SeriesIndex, now uses regular indexing properties

BUG: fixed copy (was using series method, bad)
     block filling for datetimes now ok (was filling with NaT, not iNaT)
     NaN in boolean ops now correctly handled (was not working for Datetimes)

BUG: fixed set_item in SparseFrame if only a scalar is passed (needed index)

BUG: sparse join fixed, did I break something in merge?

BUG: consolidated block slicing under _slice

BUG: added Series to santize_array
     all numeric methods now call get_values() rather than values

ENH: partial SparsePanel support

ENH: reverted SparsePanel changes, save for later
     fixed up xs in SparseFrame

BUG: SparsePanel was using an inherited as_matrix(), bad

TST: fixed shift
     default in class creation wrapper is to not pass existing fillers
     added sanitize column for generalitiy
     fixed count (in series)

CLN: modify core/expressions to use get_values()
     remove methods from SparseFrame (and use inherited):
       combine_first,icol,as_matrix,get_dtype_counts
     bug fix in core/internals/get_dtype_counts

CLN: use _values_from_object instead of direct call to get_values()

BUG: fixed set_value semantics, as it could possibily change the index

BUG: fixed tseries/period indexing
     fixed some bugs showing up in 32-bit (in nanops)

BUG: fix incorrect exception raised in indexing (on 32-bit)

BUG: fixed get_merge_keys (add Series to ndarray testing)

BUG: fixed pivot table maybe???x
     core/internals/_ref_locs will now set indexer if ref_items==items

TST: apply_reduce in tests/test_frame still failing

BUG: fixed getitem_boolean_object finally I think (was issue in set_value in Series)
BUG: fixed putmasking mess in Series, now in core/internals

BUG: more fixes

BUG: fixed core/internals/replace as choking on input

BUG: refixed groupby

BUG: fix test_where in series

BUG: fixed reindex on a sparse block (was not taking correctly)

BUG: fixed sparse filling!!!!!

BUG: fixed pivot, need to define __hash__ to raise TypeError in NDFrame

BUG: downcast argument not in SparseBlock or sparse/frame.py for fillna

BUG: fix apply_reduce?

BUG: fixes in reduce.pyx to deal with reconstrucing a Series argument to the function
     if needed

BUG: reducer now produces a Series with its index (to the called function)
     ols converts to_dense to avoid some issues

ENH: fixed core/frame/apply to accept reduce argument (default True),

     to allow turning off the reduction attempt (to preserver the column character)
     if say self.values would change it

BUG: finally fixed reducer?

BUG: reduce on frame bug (showing in py3)

BUG: ols not working with sparse

TST: stats.tests.test_ols/test_wls is not testing for the correct version

     of statsmodels (fails on 32-bit)

     PTF

TST: make sure to skip the test_wls if our version isn't enough

PERF: some perf enhancements

BUG: fix sparse/array/make_sparse to take objects and extract the arrays

PERF: series construction now much faster

PERF: improvements in core/internals

MERGE: updated to master and merged in

MERGE: more merging fixes

PERF: fixed null tests to be MUCH faster

PERF: improvements in series construction via from_array

PERF: merge improvements by using _has_sparse in bms

PERF: some improvements

PERF: more internals optimizations

CLN: Index now subclassed off of PandasObject

BUG: fixed inheritence for core/index.py (Index), solves unicode issues

BUG: some merge errors in sparse

VB: modernize the sparse vb suite

BUG: fixed merging by single item (was broker for sparse for some reason)
     names not propogating in Series constructor on _slice

BUG: add name back to series constructor

ENH: pickle compatibility for Series/SparseSeries prior to 0.12!

ENH: added pickle_compat to common/load

BUG: in core/series on fastpath and index is actually changed

     (e.g. its actually a datelike index, but is of type object),
     need to set the axis in the BlockManager

BUG: _getitem__bool only is active for Index/Int64Index (issues with DatetimeIndex/PeriodIndex)

     so default to having it call (slower) __getitem__

COMPAT: py3 compat fixes

TST: recover pickles in a particular order or names

MERGE: fixup merging with 0.11.0 final

BUG: set _subtyp in sparse (use main type of object)

BUG: fixed mergig on need to reindex sparse

BUG: fixed consolidation issue prior to merge

BUG: construction of a series with another series odd bug

BUG: fix series constructor when passed a dtype (and no copy)

BUG: fixed sparse slicing via blocks (don't use a sparse block when slicing)

BUG: fixed remaining sparse issue (SpareDataFrame was converting SparseArray incorrectly)

BUG: dtypes in groupby nth fixed (converting on aggregation item_by_item)

BUG: partial fix on groupby?

BUG: restored groupby back to master (SeriesGrouper)

BUG: more fixes on groupby

BUG: fixed all groupbys!

BUG: get_median in core/nanops.py complaining

PERF: made constructions of SparseFrame have less redundant steps

PERF: minor series perf improvement

TST: trying to fix how_lambda in tseries/resample

     PTF

PERF: addtl groupby multi_python perf improvements

PERF: speeds up for Series.__getitem__

PERF: some perf on groupby.....

      added _block, _values in SingleBlockManager

PERF: more reducer improvements

BUG: fixed SeriesBinGrouper hopefully

BUG: tseries/index.py was missing __str__ = __repr__
CLN: rebase to 0.12

BUG: groupby filter that return a series/ndarray truth testing

BUG: refixed GH3880, prop name index

BUG: not handling sparse block deletes in internals/_delete_from_block

BUG: refix generic/truncate

TST: refixed generic/replace (bug in core/internals/putmask) revealed as well

TST: fix spare_array to put up correct type exceptions rather than Exception

CLN: cleanups

BUG: fix stata dtype inference (error in core/internals/astype)

BUG: fix ujson handling of new series object

BUG: fixed scalar coercion (e.g. calling float(series)) to work

BUG: fixed astyping with and w/o copy

ENH: added _propogate_attributes method to generic.py to allow
     subclasses to automatically propogate things like name

DOC: added v0.13.0.txt feature descriptions

CLN: pep8ish cleanups

BUG: fix 32-bit,numpy 1.6.1 issue with datetimes in astype_nansafe

PERF: speedup for groupby by passing a SNDArray (Series like ndarray) object to evaluation functions
      if allowed, can avoid Series creation overhead

BUG: issue with older numpy (1.6.1) in SeriesGrouper, fallback to passing a Series
     rather than SNDArray
BLD: pep8 major changes