adapted service to run on current dm-4.1-SNAPSHOT 'master'.

changes:
- renamed occurences of CompositeValue to CompositeValueModel
- uri of "EduZEN Editors" workspace is now "de.workspaces.deepamehta"
- all migrations cleared and updated
- updated dependencies in pom.xml

to be tested:
- user roles and permissions through workspace assignment (collaborative editing)

Note: You must reset your DB.