pgsql: Remove the -P options of oid2name and pgbench, as they are

Log Message:
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Remove the -P options of oid2name and pgbench, as they are security
hazards.  Instead teach these programs to prompt for a password when
necessary, just like all our other programs.
I did not bother to invent -W switches for them, since the return on
investment seems so low.

Modified Files:
--------------
    pgsql/contrib/oid2name:
        oid2name.c (r1.32 -> r1.33)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/oid2name/oid2name.c?r1=1.32&r2=1.33)
    pgsql/contrib/pgbench:
        pgbench.c (r1.74 -> r1.75)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pgbench/pgbench.c?r1=1.74&r2=1.75)
    pgsql/doc/src/sgml:
        oid2name.sgml (r1.3 -> r1.4)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/oid2name.sgml?r1=1.3&r2=1.4)
        pgbench.sgml (r1.4 -> r1.5)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/pgbench.sgml?r1=1.4&r2=1.5)