Added to docstrings in factorize function
BUG: Conflict between thousands sep and date parser.

Fixes issue where thousands separator could conflict with date
parsing.

This is only fixed in the C parser.

Closes issue #4678
BUG: fix issue #4678 for Python parser
Fixes wrong overlapping check in _can_fast_union.

To use the fast_union method it is not enough to find an overlap, the
indices also have to be aligned.
BUG: Bug in concatenation with duplicate columns across dtypes not merging with axis=0 (originally GH4771),
     fixed again is (GH4975)
Merge pull request #4989 from jreback/merge_er

BUG: Bug in concatenation with duplicate columns across dtypes, GH4975
ENH: Make categorical repr nicer.

ENH: Support printing empty categorical.

TST: Add tests for categorical printing.

REF: Remove unnecessary unicode calls.

TST: Hack so tests pass with numpy < 1.7.x

CLN: fix DataFrame import in core/categorical.py
Merge branch 'dt_index_fix' of https://github.com/filmor/pandas into filmor-dt_index_fix

Conflicts:
	doc/source/release.rst
Merge pull request #4944 from engstrom/master

DOC: Added to docstrings in factorize function GH2916
Merge branch 'issue-4678-thousands-date-conflict' of https://github.com/guyrt/pandas into guyrt-issue-4678-thousands-date-conflict

Conflicts:
	doc/source/release.rst
CLN: fix py2to3 issues in categorical.py
Merge pull request #4990 from jreback/cat_fix

CLN: fix py2to3 issues in categorical.py
TST: fix indexing test for windows failure
Merge pull request #4992 from Komnomnomnom/indexing-dtype-test-fix

TST: fix indexing test for windows failure