VSPERF: Report percentage frameloss from IXIA/IXNET

VSPERF: Report percentage frameloss from IXIA/IXNET

The patch introduces frame_loss_percent result value.
The implementation is done for Ixia and IxNet
traffic generators. The value is visible in list
of result values at the end of the test, in csv,
rst and md files.

JIRA: VSPERF-201

Change-Id: I9b6795d427b199cb62ed66b7a137e412e36dc757
Signed-off-by: Radek Zetik <radekx.zetik@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Brian Castelli <brian.castelli@spirent.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Tv Rao <tv.rao@freescale.com>
Reviewed-by: Billy O Mahony <billy.o.mahony@intel.com>