changes descMD assignments in batch#update to appends; just in case FITS pre-populates these values, we don't want the batch operation to overwrite existing values
changes descMD assignments in batch#update to appends; just in case FITS pre-populates these values, we don't want the batch operation to overwrite existing values

ndlib/scholarsphere,ndlib/scholarsphere,samvera/hyrax,samvera/hyrax,zhang4952/scholarsphere,zhang4952/scholarsphere,zhang4952/scholarsphere,samvera/hyrax,samvera/hyrax,jeremyf/sufia,jeremyf/sufia,ndlib/scholarsphere,zhang4952/scholarsphere