Contrail work

Contrail work.

Still working on below stuffs

1. Inline documentation
2. More complete spec tests
3. Pending vrouter part - this need working nova, so working on setting up nova. Vrouter code is already there so only some small changes would be required.
setting up router is optional - this is only set if you have edge routers. So made it optional here. The contrail::config class only create that bgp object if router_ip is set.