pgbouncer - pgbouncer: switch to toggle between LIFO and round-robin

Log Message:
-----------
switch to toggle between LIFO and round-robin

Modified Files:
--------------
    pgbouncer/doc:
        pgbouncer.config.txt (r1.5 -> r1.6)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbouncer/pgbouncer/doc/pgbouncer.config.txt.diff?r1=1.5&r2=1.6)
    pgbouncer/etc:
        pgbouncer.ini (r1.3 -> r1.4)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbouncer/pgbouncer/etc/pgbouncer.ini.diff?r1=1.3&r2=1.4)
    pgbouncer/src:
        bouncer.h (r1.16 -> r1.17)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbouncer/pgbouncer/src/bouncer.h.diff?r1=1.16&r2=1.17)
        main.c (r1.17 -> r1.18)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbouncer/pgbouncer/src/main.c.diff?r1=1.17&r2=1.18)
        objects.c (r1.25 -> r1.26)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/pgbouncer/pgbouncer/src/objects.c.diff?r1=1.25&r2=1.26)