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

Coerces to object Index instead.
COMPAT: allow string concats to datetimeindex only (int/float are invalid)
DOC: moved numpydoc sphinx extension to subdirectory

Clearer distinction from ipython directive files
DOC: update numpydoc to current master (commit 223df02530)
BUG: Regression in Series with a multi-index via ix (GH6018)
CLN: Remove references to _SeriesIndexer (vestigial)
BUG/CLN: make xs a generic method
Merge pull request #6022 from jreback/series_mi

BUG: regression in GH6018, indexing with a Series multi-index
BUG: Bug in Series construction of mixed type with datelike and an integer (which should result in
     object type and not automatic conversion)
Merge pull request #6028 from jreback/series_infer

BUG: Bug in Series construction of mixed type with datelike and an integer
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)