[ns] implement IPv6 in NS 2.34

[Hafedh Guigua]

I am Guiga Hafedh, a student in research master in network in the ISITCOM
(Institut supérieur d'Informatique et des Technologies de Communication).
I am a member of the research unit PRINCE. In Hamma Sousse/ Tunisie.
I Work in the Internet of Things (IoT) and i have a problem to implement
IPv6 IN NS 2.34.
Can you help me and give me same idees to do this.