FIX MneExperiment:  assign `subject` field values `[]` when `find_subjects==False`
FIX MneExperiment.plot_annot()
STY:  eellab imports * from lab
STY EXA:  replace `eelbrain.eellab` with `eelbrain.lab`
ENH fmtxt:  `Section.add_image_figure()` allow adding image from existing file
STY fmtxt
ENH NDVar:  implement `Dimension.__eq__()`; check dimension when using NDVar index
ENH NDVar:  make boolean NDVar from comparison
FIX NDVar:  implement Dimension.__ne__()
OPT plot:  import plot.brain without importing surfer
ENH Notifier:  Drop into PDB on exception
API Notifier:  remove message stack (simplify)
OPT lm_fitter:  preallocate values array
OPT lm_fitter:  precompute effects and dfs (& STY)
STY LMFitter:  rename lm_fitter -> LMFitter; X-->x
OPT LMFitter:  pre-allocate result when splitting
API LMFitter:  .map() returns list of F-maps
API glm:  capitalization  lm -> LM, anova -> ANOVA
TEST LMFitter
OPT LMFitter:  pre-allocate everything