testcase: Add frame modification config

testcase: Add frame modification config

* Added a new standard set of flow table that defaults to routing phy1 to phy2
  and vice-versa and allows frame modification and tuple matches to be added
  independently of routing.
* Add a FrameMod testcase attribute - implement this for value 'vlan'
* With FrameMod == 'vlan' the reported tx_fps and rx_fps figures do not match
  even for RFC2544 throughtput 0% packet loss - this is a pre-existing bug
  and a fix will be done as a separate patch. The rx_fps figure is the
  reliable figure.

JIRA: VSPERF-27

Change-Id: Idd137b7a101305e7aebb6fabdfb6a7a4dcf8661b
Signed-off-by: Billy O'Mahony<billy.o.mahony@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Eugene Snider <Eugene.Snider@huawei.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Gurpreet Singh <gurpreet.singh@spirent.com>
Reviewed-by: Tv Rao <tv.rao@freescale.com>