CBD-808: add reb-vperf config with +S option

Change-Id: I6eeb3a19695b9ad83b6e86edaa0cdffb2fca75fb
Reviewed-on: http://review.couchbase.org/24377
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>
Tested-by: Pavel Paulau <pavel.paulau@gmail.com>