OPT/STY stats:  confidence_interval
STY opt:  no private function names
UPDATE opt:  Cython 0.21
FIX Factor.cells:  don’t freeze
ENH confidence_interval:  pooled variance for categorial predictor
gitignore:  PyCharm
ENH confidence_interval:  for related measures
STY plot.uv:  _plt_barplot
ENH stats:  ADD variability()
ENH Barplot:  use new variability estimates (&FIX)

FIX Var.info access for ylabel
ENH plot.UTSStat:  use pooled error variability
STY _ax_uts_stat