vnfs: Enable PVP using vhost-cuse

vnfs: Enable PVP using vhost-cuse

Enable PVP testing using vhost-cuse as guest access method

Recent changes:
* Move NEWS.md changes to NEWS.rst
* Update comment to vhost-cuse
* Restore config back to checkout state after make
* Merge OPNFV 1092 updates

* Add PVP-vhost-cuse to NEWS.md
* Add comment/example to GUEST_CORE_BINDING
* Move hardcoded values to conf/04_vnfs.conf
* Set default VNF to QemuDpdkVhostCuse
* Compile eventfd_link if VHOST_USER=n
* Use MAC and PCI address from conf
* Use vhost method in conf to properly set interface type

JIRA: VSPERF-59

Change-Id: Ib1159e216f3e25b9971c0935969680582683916b
Signed-off-by: Madarang, Dino Simeon <dino.simeonx.madarang@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>