CRUD DELETE to copy username and groupname
No user/group when publishing
- we don't have those columns in the form definition tables
- so we shouldn't try to read/write the user/group in that case
CRUD GET return operations
- done through Orbeon-Operations response header
    - can't just 403 as doesn't know what the data will be used for
    - e.g. edit and review page both do the same GET
- alternative would have been to send required operation in request
    - checking on the front-end, like what's done for the summary page
Use Orbeon-Operations headers, if present
- it might contain more operations than what we can now just based on roles
Add property for group header
Make MySQL version generic, and used for DB2