Merge pull request #6954 from jreback/overflow

BUG: Bug in sum/mean on 32-bit platforms on overflows (GH6915)
ENH: quantiles accept list like

update docs
Merge pull request #6955 from TomAugspurger/quantiles

ENH: Quantiles accepts an array
CLN: remove items/ref_items attributes from Block class

Now, there's one authoritative mapping from BlockManager axis0 to
axis0 of subordinate blocks:

* _blknos[loc] is block number where loc-th item resides
* _blklocs[loc] is location in given block of loc-th item

Blocks support this mapping with blk._ref_locs attributes that
enumerate all items contained in that block.
CLN: rename Block.ref_locs -> mgr_locs to reduce confusion

PERF: add BlockPlacement class to optimize range-like cases

CLN: unify get_slice & take/reindex ops along axis0

TST: add slicing/taking/reindexing tests for BlockManagers

CLN: remove unused code
BLD: numpy 1.9-dev requires cython for installation
Merge pull request #6745 from immerrr/refactor-blockmanager

CLN: revisit & simplify Block/BlockManager, remove axes
Force 64-bit integers to comply with cython buffer specs
COMPAT:  32-bit platform compat for Panel.count
ENH: Added NDFrame.slice_shift

added slice_shift func docs and removed freq argument
BUG: Change Panel.shift to use slice_shift #6605 #6826

TST: Make sure Panel.shift retains dtypes

DOC: removed previous doc entries for #6605

Re-add note about dropping shifted periods

DOC: added note about bug fix

don't pass on freq