Add JobPhase/@ExternalID

<Both> Table 1.5: Glossary Workstep A workstep is an individual JMF XJMF JDF XJDF process that can be processed on a single device in one pass. A workstep is comprised of one or multiple <Make unconditional> Phases parts such as setup, production or cleanup. <XJDF only> 6.59 NodeInfo The NodeInfo resource contains information about planned scheduling. It allows MIS to plan, schedule and invoice jobs or job parts <glos>Worksteps</glos>. If an MIS needs to explicitly specify an individual <glos>Workstep</glos>, it SHOULD be identified in ../Resource/@ExternalID. . <Both> Table 7.69: JobPhase Element WorkStepID ? New in <JDF>String/<XJDF>NMTOKEN If present, @WorkStepID SHALL identify the <glosWorkstep</Glos> that is described by this JobPhase. If <xjdf>ResourceSet [@Name="NodeInfo"] /Resource/@ExternalID <jdf>NodeInfo/@WorkStepID is specified, The value SHALL be copied from there. else the value MAY be generated by the device that is generating the JobPhase.