Config save support for networkconfiguration.neutron

Config save support for networkconfiguration.neutron

With the ODL ML2 Integration, the REST APIs are uni-directional, hence a simple controller restart
results in synchronization issues between Openstack/CloudStack ML2 and ODL.

The solution that was agreed with Kyle, Ryan, Hugo & others is to add the config save support on the
ODL side which will effectively remove the inconsistency issues between Openstack / Cloudstack and ODL.

Change-Id: I9c5cb1a7d4acd0c147a3014da090770b231fd8d9
Signed-off-by: Madhu Venugopal <mavenugo@gmail.com>