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
VB: modernize the sparse vb suite
BUG: some merge errors in sparse
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
BUG: fixed inheritence for core/index.py (Index), solves unicode issues
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
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