Fix to be able to read FCS data files with 'end data offset' in the FCS header specified as '99999999' rather than '0' if the real value is over '99999999' and specified in the FCS text segment. This fix is needed because certain versions of FlowJo break the FCS specification by specifying '99999999' rather than '0' in the FCS header in cases when the actual value does not fit in the FCS header.