IPv6 netowrk is advertised.
IPv6 address is used for BGP peering.
Still using IPv4 address for ONOS peering.
*.json files are updated correspondingly.
Change-Id: I8fdac12d2d25b840dcadfb261667a9f98eb9f6be
New script tutorial_ipv6.py is added.
o Switch OpenFlow version set to OpenFlow 1.3
o IPv6 forwarding is enabled
Change-Id: Ie6840f38f0d09d9afb5b5791d26f7af14c4785d6