pgsql: Fix pg_restore to complain if any arguments remain after parsing

Log Message:
-----------
Fix pg_restore to complain if any arguments remain after parsing the switches
and input file name, per bug #5617 from Leo Shklovskii. Rearrange the
corresponding code in pg_dump and pg_dumpall so that all three programs
handle this in a consistent, straightforward fashion.

Back-patch to 9.0, but no further. Although this is certainly a bug, it's
possible that people have scripts that will be broken by the added error
check, so it seems better not to change the behavior in stable branches.

Modified Files:
--------------
pgsql/src/bin/pg_dump:
pg_dump.c (r1.584 -> r1.585)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c?r1=1.584&r2=1.585)
pg_dumpall.c (r1.137 -> r1.138)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dumpall.c?r1=1.137&r2=1.138)
pg_restore.c (r1.102 -> r1.103)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_restore.c?r1=1.102&r2=1.103)