API plot-colors:  Colors -> ColorList
ENH plot.ColorGrid:  size argument

Control the size of the color squares
DOC plot:  move note on backend into `plot` module documentation
DOC plot-colors
ENH plot-uv:  add standard `tight` argument
ENH plot-brain:  save image with transparent background

(add fixed up Brain class)
WIP plot:  if tight==False, interpret subplot_params as absolute
ENH EelFigure:  ADD .set_xtick_rotation()
RF EelFigure:  collect layout parameters as *args, **kwargs
FIX plot.UTSClusters:  cluster Dialog
FIX plot.Histogram:  `pooled` argument
ENH EelFigure:  ADD `frame` and `taxis` arguments
FIX plot.Boxplot:  test=False
STY plot-uv:  _plt_barplot
FIX plot-uv:  _mark_plot_1samp font size
FIX plot-uv:  adjust pairwise connectors’ location based on `top`
FIX EelFigure:  default `tight=True`
STY plot.brain
API Result:  expose .find_clusters()
ADD plot.ColorBar