pgsql: Show oid2name command-line arguments in documentation like we do

Log Message:
-----------
Show oid2name command-line arguments in documentation like we do for
non-contrib command-line tools (no longer in a single table display).

Modified Files:
--------------
pgsql/doc/src/sgml:
oid2name.sgml (r1.6 -> r1.7)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/oid2name.sgml?r1=1.6&r2=1.7)