ENH TreeModel:  compounds

automatically update compounds composed of different elements, skipping
elements that are = ""
ENH MneExperiment:  `sns-kind` compound
ENH MneExperiment:  `evoked-kind` compound
ENH MneExperiment:  ADD option to equalize trial count in evoked files
FIX MneExperiment.load_events():  `edf` kwarg
FIX MneExperiment:  delete mne Raw from evoked-files
ENH MneExperiment:  ADD .make_test() and test-file
FIX MneExperiment:  don`t include `{model}` in evoked-kind
ENH MneExperiment.show_subjects():  return type through argument

return as fmtxt.Table or Dataset
ENH MneExperiment:  ADD .make_report_clusters()
ENH SourceSpace:  represent .parc as Factor
OPT connectivity:  use sorted array of [src, tgt]

Dimensions return connectivity as array instead of sparse matrix
ENH SourceSpace.connectivity():  ADD disconnect_parc option
ENH MneExperiment:  use `parc` for stc_ndvar()
DOC MneExperiment
FIX testnd:  anova with multiprocessing
ENH testnd:  Add simple threshold-free permutation test
ENH testnd:  don’t precompute clusters

- ClusterDist has .clusters() method
- TestResult have .clusters as LazyProperty
ENH NDVar:  make .__getitem__() use .sub()
ENH NDVar:  Allow boolean NDVar as argument in summary methods