CA-105894: Adding the logic needed to recurse when dealing with a VLAN PIF. Use the VLAN reference to obtain the PIF through which tagged traffic is being sent.

Signed-off-by: Rob Dobson <rob@rdobson.co.uk>
Merge pull request #13 from rdobson/ca-105894

CA-105894: Adding the logic needed to recurse when dealing with a VLAN P...