added a check for an existing registration before a reg petition can be approved
added a check for an existing registration before a reg petition can be approved

git-tfs-id: [https://tfs.caes.ucdavis.edu:8088/tfs]$/Commencement/Trunk/Commencement;C9181

ucdavis/Commencement,ucdavis/Commencement,ucdavis/Commencement