fixup
[lib.nfv.config] Improve selftest.
Change test_fixtures/nfvconfig/test_functions/same_vlan.ports MAC settings.
[bench_env] Added host-nic-snabbnfv-guests.sh for testing
snabbnfv-traffic.
[lib.nfv] Added intial selftest.sh .
[lib.nfv.config] Fix broken configuration logic with regards
to L2TPv3 and nd_light.