CBQE-1225: large bucket kv stress test

Change-Id: Iac4ad2cae090352c390cd7836cd7e5d3bbe79a30
Reviewed-on: http://review.couchbase.org/26887
Reviewed-by: Tommie McAfee <tommie@couchbase.com>
Tested-by: Tommie McAfee <tommie@couchbase.com>