pgsql: Fix seriously broken markup for libpq-envars cross-references.

Log Message:
-----------
Fix seriously broken markup for libpq-envars cross-references.

Modified Files:
--------------
    pgsql/doc/src/sgml/ref:
        clusterdb.sgml (r1.20 -> r1.21)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/clusterdb.sgml.diff?r1=1.20&r2=1.21)
        createdb.sgml (r1.43 -> r1.44)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/createdb.sgml.diff?r1=1.43&r2=1.44)
        createlang.sgml (r1.39 -> r1.40)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/createlang.sgml.diff?r1=1.39&r2=1.40)
        createuser.sgml (r1.46 -> r1.47)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/createuser.sgml.diff?r1=1.46&r2=1.47)
        dropdb.sgml (r1.30 -> r1.31)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/dropdb.sgml.diff?r1=1.30&r2=1.31)
        droplang.sgml (r1.29 -> r1.30)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/droplang.sgml.diff?r1=1.29&r2=1.30)
        dropuser.sgml (r1.35 -> r1.36)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/dropuser.sgml.diff?r1=1.35&r2=1.36)
        initdb.sgml (r1.42 -> r1.43)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/initdb.sgml.diff?r1=1.42&r2=1.43)
        pg_ctl-ref.sgml (r1.40 -> r1.41)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_ctl-ref.sgml.diff?r1=1.40&r2=1.41)
        pg_dump.sgml (r1.96 -> r1.97)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_dump.sgml.diff?r1=1.96&r2=1.97)
        pg_dumpall.sgml (r1.67 -> r1.68)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_dumpall.sgml.diff?r1=1.67&r2=1.68)
        pg_restore.sgml (r1.69 -> r1.70)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_restore.sgml.diff?r1=1.69&r2=1.70)
        psql-ref.sgml (r1.189 -> r1.190)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/psql-ref.sgml.diff?r1=1.189&r2=1.190)
        reindexdb.sgml (r1.4 -> r1.5)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/reindexdb.sgml.diff?r1=1.4&r2=1.5)
        vacuumdb.sgml (r1.39 -> r1.40)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/vacuumdb.sgml.diff?r1=1.39&r2=1.40)