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.
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)
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
BUG: Bug in to_datetime with a format and coerce=True not raising (GH5195)
Merge pull request #5197 from jreback/to_datetime

BUG: Bug in to_datetime with a format and coerce=True not raising (GH5195)
inlined some functions and avoid repeated conversion factor calculation when using period_asfreq_arr in period.c
BUG/TST: Test filter corner cases, and treat NaN as False.
DOC: Note -> Notes (numpydoc docstring section)
DOC: make api docs reflect api usage (#4539)