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.
Basically both of them are bgp objects in contrail config node, one if of contrail bgp control node and other is edge router. 

If you think they must be different, it is just doable and code would be simpler too.