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.
ENH: add to_dataframe method to Series
RVT: revert 4912 change of 4030 nose import bug
Merge pull request #5170 from cpcloud/remove-debug-and-move-nose

RVT: revert 4912 change of 4030 nose import bug
DOC: whatsnew.rst,missing_data.rst,io.rst updates
DOC: update readme.md for bq/excel deps
DOC: readme.md updates
Merge branch 'series_to_dataframe' of https://github.com/drasch/pandas into drasch-series_to_dataframe

Conflicts:
	doc/source/v0.13.0.txt
API: make allclose comparison on dtype downcasting (GH5174)
TST: update interpolate tests to account for correct dtype inferernce
Merge pull request #5177 from jreback/infer

API: make allclose comparison on dtype downcasting (GH5174)
PERF: calling get_indexer twice when a specialized indexer (e.g. pad) could be called instead
Merge pull request #5178 from jreback/perf_reindex

PERF: calling get_indexer twice when a specialized indexer (e.g. pad) could be called instead
BUG: Fix segfault on isnull(MultiIndex)

Now raises NotImplementedError b/c not yet clear what it should return.
Merge pull request #5125 from jtratner/fix-segfault-mi-isnull

BUG: Fix segfault on isnull(MultiIndex)
TST: addtl pytables tests
Merge pull request #5180 from jreback/pytables_clean

TST: addtl pytables tests
DOC: multi-index update on cookbook.rst
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.)
DOC/CLN: fix a few typos that were causing Sphinx warnings

Also clean up interpolate and a little bit rewording in bigquery docs
Merge pull request #5169 from cpcloud/doc-build-fixes

DOC/CLN: A few fixes and cleanup for doc warnings/errors