BUG: Dont add None to plot legend.
Merge pull request #8536 from TomAugspurger/plot-label-none

BUG: Dont add None to plot legend.
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