GenericNetwork resource as a copy of ofnetwork.

- atrifactid changed to genericnetwork.
- packages renamed to org.opennaas.extensions.genericnetwork.*
Rename OFNetwork* classes to GenericNetwork*.
Rename resource type to genericnetwork.
Circuit concept in genericnetwork model.
Map storing implementation for each circuit.
Xml namespace in all classes in genericnetwork.model.
Merge pull request #822 from isartcanyameres/feature/generic-network-resource

Feature/generic network resource