Release/0.23

Release 0.23

New features (see #684 ):
- Introduces OFERTIE NCL controller with required OpenNaaS resources:
- OpenFlow Switch Resource with OpenFlowForwarding capability
- Floodlight driver for components above
- SDN network Resource with OpenFlow provisioning capability
- Internal driver for component above.


Fixes:
- Avoids DOSGi concurrent modification exception in OpenNaaS console. 
- Fixes some errors in generated release binaries
- Fixes some errors in integration tests
- Unifies codestyle