PERF: Performance improvement for MultiIndexes with a DatetimeIndex level
DOC: Clean Cookbook Issues: Tabs, expanded_apply, axis aliasing, etc.
Merge pull request #8535 from jnmclarty/cookbook_inline_examples

DOC: Clean up Sphinx Issues, fix tabs, in Cookbook
Merge pull request #8544 from mtkni/master

PERF: Performance improvement for MultiIndexes with a DatetimeIndex levels
DOC: v0.15.0 corrections
DOC: Update ecosystem.rst: Add IDE, IPython, qgrid, Spyder, API, quandl, Out-of-core, Blaze

DOC: Update ecosystem.rst: Add IDE, IPython, API
DOC: Update ecosystem.rst: Add GUI > Spyder
DOC: Update ecosystem.rst: GUI -> IDE, IPython > qgrid, API
DOC: Update ecosystem.rst: -> IDEs
DOC: Update ecosystem.rst: depluralize
DOC: Update ecosystem.rst: Add IPython [Notebook] description; alphabetize
DOC: Update ecosystem.rst: add Blaze, alphabetize
Merge pull request #8507 from westurner/patch-3

DOC: Update ecosystem.rst: Add IDE, IPython, qgrid, Spyder, API, quandl, Out-of-core, Blaze
PERF: Slowness in multi-level indexes with datetime levels

Special case handling of sliced multi indexes, where there the length of the level values may exceed the length of the index.
Corrected nan handling issue introduced by the original change. (+1 squashed commit)
Squashed commits:
[0dae170] PERF: Slowness in multi-level indexes with datetime levels

Special case handling of sliced multi indexes, where there the length of the level values may exceed the length of the index.
PERF: fixup datetime_index repr perf (GH8556)
Merge pull request #8557 from jreback/dt_perf

PERF: fixup datetime_index repr perf (GH8556)
DOC: formatting issue in scatter_matrix section
DOC/FIX: In R it's still levels...
Merge pull request #8561 from JanSchulz/r_levels

DOC/FIX: In R it's still levels...
BUG: _Openpyxl2Writer mishandles merged cell style

TST: Cover merged cells case in openpyxl2 engine
Merge pull request #8549 from mtkni/master

PERF: Slowness in multi-level indexes with datetime levels (part 2)
DOC: fix formatting read_csv comment kwarg explanation
DOC: ignore_na warning
Switch default colormap for scatterplot to 'Greys'

In #7780, I added colormap support to scatter, but choose to override the
default rainbow colormap (7780#issuecomment-49533995).

I'm now regreting choosing 'RdBu' as the default colormap. I think a simple
black-white colormap is a more conservative and better default choice for
coloring scatter plots -- binary colormaps really only make sense if the data
is signed. 'Greys' is also the default colormap set by the seaborn package,
and @mwaskom has done far more thinking about colormaps than I have.

If possible, I would love to get this in before 0.15 is released, so we don't
have to worry about changing how anyone's plots look.

CC @sinhrks
Merge pull request #8567 from seth-p/ignore_na_warning

DOC: ignore_na warning
Merge pull request #8566 from shoyer/fix-default-cmap

Switch default colormap for scatterplot to 'Greys'