pgsql: Cope with circularities involving a view's ON SELECT rule.

Log Message:
-----------
Cope with circularities involving a view's ON SELECT rule. I originally
thought there couldn't be any, but the folly of this was exposed by an
example from andrew(at)supernews(dot)com 5-Dec-2004. The patch applies the
identical logic already used for table constraints and defaults to ON
SELECT rules, so I have reasonable confidence in it even though it might
look like complicated logic.

Modified Files:
--------------
pgsql/src/bin/pg_dump:
pg_dump.c (r1.395 -> r1.396)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c.diff?r1=1.395&r2=1.396)
pg_dump.h (r1.113 -> r1.114)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.h.diff?r1=1.113&r2=1.114)
pg_dump_sort.c (r1.6 -> r1.7)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump_sort.c.diff?r1=1.6&r2=1.7)