Feature/ospfv3

If we wanted to use ipv6 interfaces in our ospf configuration, we needed to implement OSPFv3 as a new router capability. Routers can configure  both OSPFv2 and OSPFv3.
The main differences in the new capability are:

- Actions: Templates contain <ospf3> and OSPFServices must use OSPFv3 algorithm type.
Capabiltty: Builds OSPFServices with OSPFv3 algorithm.

Also OSPFCapability was refactored to include OSPFv2 algorithm type.