BUG: Fix DatetimeIndex.insert() with non-datetimes.

Coerces to object Index instead.
COMPAT: allow string concats to datetimeindex only (int/float are invalid)
BUG: Fix to_datetime to properly deal with tz offsets #3944

Currently for certain formats of datetime strings, the tz offset will
just be ignored.
DOC: moved numpydoc sphinx extension to subdirectory

Clearer distinction from ipython directive files
DOC: update numpydoc to current master (commit 223df02530)
Escape special characters in to_latex()
Merge pull request #5374 from bjornarneson/patch-1

Escape special characters in to_latex() output
PERF: vbenches for DataFrame.apply
PERF: perf enhancements for DataFrame.apply (GH6013)
TST: check appropriate tests for apply
PERF: allow apply to use the fast-path in mixed type frames except where datelike
      are present
Merge pull request #6024 from jreback/apply_perf

PERF: apply perf enhancements
BUG: Possible segfault when chained indexing with an object array under numpy 1.7.1 (GH6026)
Merge pull request #6031 from jreback/index_segfault

BUG: Possible segfault when chained indexing with an object array under numpy 1.7.1 (GH6016)
DOC: be more vague in enhancingperf.rst GH6013
TST: fix test that repr returns str
BUG: less false positives with SettingWithCopy (GH6025)
Merge pull request #6040 from dsm054/fix-test-that-repr-returns-str

TST: fix test that repr returns str
BUG: Bug in setting using fancy indexing a single element with a non-scalar (e.g. a list),
    (GH6043)
Merge pull request #6044 from jreback/ix_list

BUG: Bug in setting using fancy indexing a single element with a non-scalar (e.g. a list) (GH6043)
Merge pull request #6042 from jreback/setting_with_copy

BUG: less false positives with SettingWithCopy (GH6025)