ENH load.tsv():  add ignore_missing argument
FIX ClusterDist:  use proper time slice for cropping
ENH NDVar:  unify methods for summary over axes &TEST
OPT:  rms function (remove avg reference option)
ENH MneExperiment:  make parc values dynamic through ._eval_parc()
DOC MneExperiment:  proper error message ...

...when set() results in invalid value
WIP ClusterDist:  multiprocessing
DOC testnd:  better error message for invalid kwargs
ENH SourceSpace:  allow .index_for_label() with string
WIP SETUP:  use setuptools upload_docs
ENH ClusterDist:  slices of TFCE results
AMD MP
AMD MP
AMD MP
AMD MP
AMD aggregate dist