DOC subp:  better error messages for FREESURFER_HOME search
RF permutation:  sign-flip iterate over indices
ENH MneExperiment:  add scaled source spaces to cache manager
ENH Dataset.save_tex():  add midrule option (default True)
DOC:  add PYPI to see also
STY:  anova
OPT opt:  use malloc for betas
STY TEST
API/ENH:  plot.configure_backend() -> plot.configure() with `show` param
PROFILE lm long
FIX opt:  use unsigned integers for indexes
FIX stats.betas():  don’t use scipy (it can’t handle big arrays)
SETUP:  remove requirements that require compiling
FIX testnd.ttest_1samp:  y with dim > 1
DOC MneExperiment:  check that .label_events() returns a Dataset
FIX plot:  find_fig_vlims
ENH plot.Array:  expose `x`, `vmax` and `vmin` arguments
DOC installing
DOC intro
FIX permutation:  sign-flip for n > 32