L3 Neutron plumbing

Converge neutron events needed to support l3 into an adapter class.
With this change all plumbing needed for northbound l3 support is completed.
Next is the 'brains' to turn the l3 related events into rules that can be used
by the multi-tenant router forwarding provider.

    Script for creating coke tenants in devstack:
    https://gist.github.com/1ba897e7cde8dbd87fe8

    Starting odl command:
    ./run.sh -virt ovsdb -Xms40m -Xmx1024m -XX:MaxPermSize=1024m

    LogLevel:
    setLogLevel org.opendaylight.ovsdb.openstack.netvirt.providers.OF13Provider trace
    setLogLevel org.opendaylight.ovsdb.openstack.netvirt.api.EventDispatcher trace
    setLogLevel org.opendaylight.ovsdb.openstack.netvirt.SouthboundHandler debug
    setLogLevel org.opendaylight.ovsdb.openstack.netvirt.PortHandler debug
    setLogLevel org.opendaylight.ovsdb.openstack.netvirt.NeutronL3Adapter debug

    Log of test:
    createTenants: https://gist.github.com/7dadd30bde5d07bb0ba1
    osgi: https://gist.github.com/4ec66a6e76908eeffcbc

Change-Id: I1570d536728ea29c2615ddca422379ad8fe70d45
Signed-off-by: Flavio Fernandes <ffernand@redhat.com>
Merge "L3 Neutron plumbing"