CBQE:0 Support for tuning per-replication settings + new settings for Sherlock + support for filtering

Eg: ./testrunner -i local.ini  -t xdcr.xdcrTopologyTests.XDCRTopologyTest.load_with_ops,items=10000,rdirection=unidirection,ctopology=chain,replication_type=xmem,default@C1=filter_expression:loadOne,checkpoint_interval:60,failure_restart_interval:20,timeout_percentage:60

Change-Id: I5297b2008688065ac7da1030280ec1588f38407f
Reviewed-on: http://review.couchbase.org/43915
Reviewed-by: Aruna Piravi <aruna@couchbase.com>
Tested-by: Aruna Piravi <aruna@couchbase.com>