FIX/RF SourceSpace:  connectivity
FIX MneExperiment._set_test_options():  include sensor space baseline
ENH resample():  seed random state
OPT testnd:  use edge connectivity in merge_labels
ENH morph_source_space():  treat scaled fsaverage appropriately
API morph_source_spaces() arg order:  vertices_to, morph_mat
WIP GUI
WIP GUI:  incorporate SelectEpochs GUI
WIP GUI:  auto-run
WIP GUI
WIP plot:  `frame` argument
DOC plot
WIP _mne:  combine_source_spaces()