BF: minor bugs fixes

Fixed:
- rois are expected to sit in the 'rois' folder
- globClock now used by idle_event and documented
- trialList is assigned to self in the docstring
- behavioral files are sorted upon reading
BF: extraInfo and runParams are not required to be discoverable
BF: GaborJet default dissimilarity comes from super now

ENH: HMAX runtime output nicer
ENH and BF: verified up to plot_timecourse

ENH: fixation condition label can be passed
ENH: offset and dur are accepted, defaults set
BF: if analysis folder already exists, don't crash
BF: plot handling is improved
ENH: printing subjID forced with flush
ENH: rois are supposed to sit in the 'rois' folder
ENH: nii and nii.gz accepted
BF: images are always sorted upon reading
ENH: offset can be None; inferred automatically
ENH: events can have unequal length for plotting
RF: plotChunks -> plot_chunks
BF: plot_chunks works :)
ENH: if baseline is too short, average across time
ENH: plot_roi works
BF: plot_timecourse works