ENH datasets:  add MNE loader
TEST mne source space connectivity
ENH TreeModel:  incorporate .exclude
ENH FileTree:  ADD .rename_field()
ENH FileTree:  exclude parameter defaults (False in file operations)
FIX FileTree.get():  raise exception if make=True and no make handler is specified
ENH MneExperiment:  ADD .make_mov_ga_dspm()
ENH MneExperiment.load_inv():  don't require riff file as input
ENH:  add `labels_from_clusters()`
WIP ENH:  source_induce_power()