comments and method doc fixes in cert_util
comments and method doc fixes in cert_util

tcmitchell/geni-tools,GENI-NSF/gram,ahelsing/geni-tools,GENI-NSF/gram,plantigrade/geni-tools,ahelsing/geni-tools,tcmitchell/geni-tools,GENI-NSF/gram,plantigrade/geni-tools