Adding TTP augmentation to inventory node

This creates a ttp-capable-node augmentation of inventory node which allows
inventory nodes to have one active TTP and a list of supported TTPs.

This patch also removes the spurrious dependency on openflowjava as well as some
dependencies on IETF YANG models.

Change-Id: I7dbab7a25bda7a9cce72babdd33b6d7d10b9a1b3
Signed-off-by: Colin Dixon <colin@colindixon.com>