Update NwbFile.m : Generate uuid if no identifier is given for file#839

ehennestad wants to merge 3 commits into

mainNeurodataWithoutBorders/matnwb:mainfrom

set-identifier-using-uuid-if-not-providedNeurodataWithoutBorders/matnwb:set-identifier-using-uuid-if-not-providedCopy head branch name to clipboard