BLTI-220

Make it so FOORM Does not add "not null" to the columns when a field is "required" in the model.

This makes migrations more difficult and the software can enforce the required bits in the 
insert and update code as it sees fit.



git-svn-id: https://source.sakaiproject.org/svn/basiclti/trunk@121290 66ffb92e-73f9-0310-93c1-f5514f145a0a