pgsql: Add the new psql command \drds to the psql docs, help and tab

Log Message:
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Add the new psql command \drds to the psql docs, help and tab completion.

I also thank Bernd Helmle for the documentation help on the previous settings
patch, which I forgot on the commit message.

Modified Files:
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    pgsql/doc/src/sgml/ref:
        psql-ref.sgml (r1.230 -> r1.231)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/psql-ref.sgml?r1=1.230&r2=1.231)
    pgsql/src/bin/psql:
        help.c (r1.153 -> r1.154)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/help.c?r1=1.153&r2=1.154)
        tab-complete.c (r1.185 -> r1.186)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/tab-complete.c?r1=1.185&r2=1.186)