more flexible inputs

[CPernet]

changes in pop_importbids https://github.com/sccn/EEG-BIDS/blob/allows-subject-and-run-names-rather-than-integers/pop_importbids.m

takes {'sub-XXX','sub-XXX'} or {'XXX','XXX'} as input rather than integers -- but integers still work (changes here https://github.com/sccn/EEG-BIDS/blob/allows-subject-and-run-names-rather-than-integers/pop_importbids.m#L243)

takes {'XXX','XXX'} for run (because of '1' vs '01') -- but integers still work (changes here https://github.com/sccn/EEG-BIDS/blob/allows-subject-and-run-names-rather-than-integers/pop_importbids.m#L844 ; you may not like that one, introducing a more recent extract function)

-- still issue with finputcheck as now takes only cells even if integer can work (and we want to keep things backcompatibe)