Add a VIF driver for IOVisor engine

Implements blueprint iovisor-vif-driver

Unit Test is included
Follows the same structure that OVS and Qbh drivers
Includes the rootwrap config to allow calls to ifc-ctl for managing IOVisor engine.

Change-Id: I346b4d84a6e48d56f307349ed681355d26710ecd
Merge "Add a VIF driver for IOVisor engine"