integration: Support of PVP and PVVP integration TCs

integration: Support of PVP and PVVP integration TCs

Integration TC support has been enhanced to support PVP
and PVVP scenarios. Definition of integration testcases
have been modified to use a sort of macros for repetitive
parts.
Additional improvements were introduced:
* instances of testcases are created only for testcases
selected for execution
* new TC definition options allow to define test specific
vswitch, VNF, traffic generator and test options
* tests filter applied on pattern specified by --tests
allows to define negative filter only; In that case
list of all tests is used as base for negative filter.
* traffic values defined within teststep passed to send_traffic
is merged with default values; This is essential for execution
of TCs with linux_bridge or SRIOV support. It also simplifies
integration TC definition
* typos removed

Change-Id: Icb734a7afd7e5154f27a8ff25615a39e01f58c27
JIRA: VSPERF-213
JIRA: VSPERF-216
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Christian Trautman <ctrautma@redhat.com>
Reviewed-by: Brian Castelli <brian.castelli@spirent.com>