via alter_field to a column in Postgres Producer
* Added a working mechanism for naming foreign keys in the PostgreSQL producer
* Fix PostgreSQL ignoring default values with specified data type
+* Fix PostgreSQL parser support for (N)::int defaults (patch by Tina Müller)
* Fix possible name duplication in SQLlite producer
* Oracle does not accept ON DELETE/UPDATE RESTRICT (though it is the actual default)
fix by not adding the ON DELETE/UPDATE clause at all