Support :autoincrement for Postgres on table creation by rebuilding what Postgres...

Support :autoincrement for Postgres on table creation by rebuilding what Postgres is doing when using the serial tye. view-class-slot-definition-mixin: add new slot autoincrement-sequence. database-make-autoincrement-sequence: new generic function/method. database-generate-column-definition: specialize for postgresql-db. database-last-auto-increment-id: honor autoincrement-sequence. database-last-auto-increment-id: use :int for result-types, not integer.