agent: Processing agent side originted messages with route change

VnswInterfaceListener is now able to react to events requiring it
to alter route, originating from the agent side.
agent: Processing agent side originted messages with route change

VnswInterfaceListener is now able to react to events requiring it
to alter route, originating from the agent side.

Post-review changes.
Merge pull request #18 from Semihalf/dev-vnswif-listener-freesbd-events

agent: Processing agent side originted messages with route change