Comment 0 for bug 1417451

The SQL User and Group entities store their domain_id. Even though we have tried to cut the linkage between the identity and resource/assignment components - it turns out that the User & Group SQL entities still mark domain_id as a foreign key back to the domain table in resource. This stops proper decoupling between our components (and, for instance, makes it hard to hand domain deletion via notification).

We should drop the domain_id FK constraint on User & Group entities.