Since there didn't seem to be anyone objecting to the notion of
decoupling UNIQUE from SERIAL, I'm going to go ahead with
reviewing/applying Rod's recent patch that does that (and fixes pg_dump
to dump 7.3 serials correctly). We can continue to debate about
the merits of making additional changes in SERIAL behavior, of course,
but this is the one that pg_dump needs.
regards, tom lane