Re: some more include removal from headers

Hello,

Here's low-hanging fruit I noticed while eyeballing a patch in the
commitfest.  This removes pg_publication.h from utils/rel.h, which is
really nice because pg_publication includes objectaddress.h which in
turn includes parsenodes.h (an absolute disaster we have there, harder
to cleanup; not in the mood).  But this here is nice and well contained.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/