ENH mne_experiment:  set_env() on __init__
ENH mne_experiment.state(): don't show long (>60 chars) values
ENH mne_experiment:  make source space
FIX push
ENH mne_experiment:  import SelectEpochs parent module for debugging
DOC examples:  add mne_sample_loader example
ENH plot.utsnd:  classify to support .set_vlim()
ENH ndvar:  time-frequency transform with cwt_morlet
WIP data:  DOC
ENH data-obj:  Dimension intersection
FIX ndvar:  Scalar dimension and tft with morlet wavelets
WIP ENH plot:  Xax argument accepts dimension [needs DOC]