Adjust the index of the new inserts during the "run" phase
Adjust the index of the new inserts during the "run" phase

The first instance will start with no offset. All other instances
will increment by the initial number of items.

       <  load  > <                 run                >
    0: [........] [inserts]
    1: [........]           [inserts]
    2: [........]                     [inserts]
    3: [........]                               [inserts]

Change-Id: I83236bf3cefd3a965350d4e8a4afbc6480d1d98f
Reviewed-on: http://review.couchbase.org/76660
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Pavel Paulau <dd88eded64e90046a680e3a6c0828ceb8fe8a0e7@gmail.com>

couchbase/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner,couchbase/perfrunner