Updates to work with Activiti 5.12 engine and include fix to avoid using custom serializer on primitive object class types, update to grails way of prompting User and Role domain classes during install

 Committer: Andy Coulson <acoulson@ACOULSON-DT.amer.corp.natinst.com>
Merge pull request #14 from acoulson2000/master

Updated to support Activiti Engine 5.12 and Grails 2.1