Add legend.facecolor and edgecolor to rcParams.
Tweak legend colors in ggplot style file.
validate_color can accept and return None
legend.facecolor and edgecolor default to None
legend.facecolor/edgecolor described in whats_new
legend updates in matplotlibrc.template
pep8 error: too many blank lines in legend.py
BUG : changed default values of legend.*color -> None
TST : added tests for legend.*color rcparams
Merge pull request #1 from tacaswell/legend_rcparams

Legend rcparams
Merge pull request #3792 from mrkrd/master

ENH : added legend.edgecolor and legend.facecolor rcparams

Merged locally to discard a commit + it's reversion.