Add pandas cookbook to tutorials (for #5837)
ENH: Refactor code to add is_view method for Series.
DOC: Add is_view to release notes
Merge pull request #5853 from jseabold/add-is-view-series

ENH: Refactor code to add is_view method for Series.
DOC: release notes
DOC: release notes
Revert "DOC: release notes"

This reverts commit 8788aff6d8b6e50c2b1252da36dfe9f4d24e3168.
Revert "DOC: release notes"

This reverts commit 2a8cd09acbe78e5b325f14082de2b0b496af2747.
Revert "Merge pull request #5853 from jseabold/add-is-view-series"

Following discussion in GH5853, reverting the change to revisit
in 0.14.

This reverts commit 91d6f1bb98a439687a31880cfcc8431d12d077c6, reversing
changes made to ee92c756f06b31efbf636185e8c2b4a5e607e808.
BUG: Series.sort will raise a ValueError (rather than a TypeError) on sorting an
     object that is a view of another (GH5856`, GH5853)

API: DataFrame._ixs will properly record a cache change (similar to _get_item_cache)
COMPAT: add different numexpr versions for testing
        skip encoding tests on too low tables versions
Merge pull request #5860 from jreback/tables_fix

COMPAT: add different numexpr versions for testing / skip encoding tests on too low tables versions
Merge pull request #5859 from jreback/series_view

rework Series.sort is_view check on underlying ndarray inplace sort (GH5856)
BUG/TST: Fixes isnull behavior on NaT in array. Closes #5443

common._isnull_ndarraylike(...) uses lib.isnullobj to check
nulls/NaN/NaT in ndarray, which in turn relies on util._checknull.
_checknull did not know about NaT, but now lib.isnullobj does, while
still maintaining performance by doing arr[i] only once.

Added a test case test_isnull_nat() to test_common.py and
check for NaT in lib.isnullobj. pd.isnull(np.array([pd.NaT]))
now yields the correct results ([True]).
Merge branch 'master' of https://github.com/commonlisp/pandas into commonlisp-master
DOC: release notes (GH5443)
BUG: bug in `o_datetime when passed a np.nan or integer datelike and a format string (GH5863)
Merge pull request #5864 from jreback/to_datetime

BUG: bug in to_datetime when passed a np.nan or integer datelike and a format string (GH5863)
BLD: enhancements to print_versions.py
DOC: updated compare w r