reconfig Damien toy builder for MRW perf testing

Change-Id: I58fd6648264152c79b550e20f2b0b41cdafbccfc
Reviewed-on: http://review.couchbase.org/28824
Reviewed-by: Sundararaman Sridharan <sundar.sridharan@gmail.com>
Tested-by: Sundararaman Sridharan <sundar.sridharan@gmail.com>