Integration Test: 4 serial VMs testcases.

Integration Test: 4 serial VMs testcases.

Implementation of RFC2544 throughput/back2back and
continuous testcases with 4 serial VMs.

Topology is: Phy1-VM0-VM1-VM2-VM3-Phy2.

This patch requires Patch VSPERF-326 "Integration test
implementation: Multi-PVP with explicit Flows".

v2: rebased to master to fix conflicts.

JIRA: VSPERF-364

Change-Id: Ib731bf6dc4634d6347b1c521bb82326db90a6c63
Signed-off-by: Antonio Fischetti <antonio.fischetti@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Martin Klozik <martinx.klozik@intel.com>