Bugfix: Prevent configuration paths to contain python keywords
fix variable overwriting in radviz

The variable `n` is set to number of rows in dataframe, and then it overwritten with number of columns, but after that there is loop that should iterate over rows and it uses new value in `n` that holds number of columns already.
ENH/TST/DOC: Implement experimental io.excel._Openpyxl2Writer
Merge pull request #8199 from stas-sl/patch-1

BUG: fix variable overwriting in radviz
BUG: Auto-detect terminal size on max_col/max_row==0
API: accept -1 for layout
Merge pull request #8297 from TomAugspurger/neg-layout

API: accept -1 for layout in plot functions
VIS: default LinePlot rotation of 0
DOC: need blankline for example
Added test and fix for insertion of empty table bug
CLN PEP8 on format.py
Merge pull request #8316 from artemyk/empty_table_insert

BUG: Exception raised when `to_sql` used to insert empty dataframe
Merge pull request #8286 from iwschris/pep8_format

CLN Pep8 on format.py
Merge pull request #7781 from germangh/master

BUG: Prevent config paths to contain python keywords
TST: py2.6 test fix in test_graphics.py
BUG: Bug in .at that would accept integer indexers on a non-integer index and do fallback (GH7814)
Squashed commit of the following:

commit d44dc582d48b7d1929c2f5de82dae758298011e2
Author: Michael Mueller <michaeldmueller7@gmail.com>
Date:   Wed Sep 3 21:11:06 2014 -0400

    Minor doc fixes

commit 8c23e228f2aae640c23743b6d5532d70b354286c
Author: Michael Mueller <michaeldmueller7@gmail.com>
Date:   Wed Aug 20 10:30:17 2014 -0400

    Referenced new parameter float_precision in docstrings and changelog

commit 820222b82f41db717e3916c5f94b8ea81cbe38be
Author: Michael Mueller <michaeldmueller7@gmail.com>
Date:   Wed Aug 20 09:42:26 2014 -0400

    Switched to function pointers, added benchmark

commit 06bd35ac08487d6079c39c1e556a197cc1766e92
Author: Michael Mueller <michaeldmueller7@gmail.com>
Date:   Sat Aug 16 10:27:19 2014 -0400

    Wrote test for precise converters

commit 73d15e651c5de2d70b027fc77156cbaa4d497213
Author: Michael Mueller <michaeldmueller7@gmail.com>
Date:   Fri Aug 15 23:57:33 2014 -0400

    Added precise converter
Merge pull request #8320 from jreback/fallback

BUG: Bug in .at that would accept integer indexers on a non-integer index and do fallback (GH7814)
Merge pull request #8044 from amras1/new-float-conversion

Added parameter float_precision to CSV parser
Merge pull request #8301 from TomAugspurger/default-rot

VIS: default LinePlot rotation of 0