TST: Tests and fix for unhandled data types in Excel writers.

Added tests and a fix for unhandled numpy data types in the
Excel writers. Issue #3122.
BUG: apply Timestamp to resultant datetimes when operating on offsets
fix replacement key for deprecated option `display.height`

replacement key for deprecated option `display.height` was set to `display.height` itself. I believe it should be `display.max_rows` instead.

This avoid a weird message in `describe_option()` :

    display.height: [default: 60] [currently: 60]
    : int
            Deprecated.
	    (Deprecated, use `display.height` instead.)
BUG: Allow duplicate indices when performing operations that align (GH5185)
CLN/BUG/ENH: Raise AttributeError with pd.options

It's called OptionError now and it subclasses both AttributeError (for
hasattr) and KeyError (for backwards compatibility). Hurray!
DOC: cleanups
Revert "DOC: cleanups"

This reverts commit bd1dbe7e0ee9db364a146eda74b0ddd050dd3903.
DOC: cleanups
Merge pull request #5188 from jtratner/fix-hasattr-on-options-object

CLN/BUG/ENH: Raise AttributeError with pd.options
ENH: Add date_format keyword to to_csv()

DOC: add date_format to release notes
DOC: minor whatsnew changes
Merge pull request #5187 from jreback/dup_ops

BUG: Allow duplicate indices when performing operations that align (GH5185)
DOC: whatsnew changes
Merge branch 'to_csv_date_format' of https://github.com/qwhelan/pandas into qwhelan-to_csv_date_format

Conflicts:
	doc/source/v0.13.0.txt
BUG: Make Index, Int64Index and MI repr evalable

Only talking about Index, Int64Index and MultiIndex. Tseries indices
(like PeriodIndex and DatetimeIndex) are more complicated and could be
covered separately.
Merge pull request #5077 from jtratner/fix-mi-repr

BUG: Make Index, Int64Index and MI repr evalable
BUG: raise NotImplementedError on passing of compound dtypes in constructors (GH5191)
Merge pull request #5192 from jreback/compound_dtypes

BUG: raise NotImplementedError on passing of compound dtypes in constructors (GH5191)
BUG: Bug in comparing duplicate frames (GH4421) related
BUG: Bug in describe on duplicate frames
Merge pull request #5194 from jreback/dup_eq

BUG: Bug in comparing duplicate frames (GH4421) related