Update notes for submitted changes

* 1. Extract IPv4 address from standard port group attached to contrail    vrouter VM as vRouter IP address to be used to send port attach    and detach notifications 2. Ignore contrail vrouter VM since it does not need to be reflected    in the VNC DB 3. Ignore distributed virtual portgroups attached to contrail dvswitch    that do not have a PVLAN spec attached since those do not need    to be reflected in the VNC DB