Cisco N1kv: Remove vmnetwork delete REST call on last port delete

Remove the vm network delete call to the VSM on final port call and
ensure that vm network is deleted from the database when the port count
becomes 0.

Change-Id: I6c08a099adfce2fdba8eefec6aadeb68a780ac37
Closes-Bug: 1373547
Add database relationship between router and ports

Add an explicit schema relationship between a router and its ports. This
change ensures referential integrity among the entities and prevents orphaned
ports.

Change-Id: I09e8a694cdff7f64a642a39b45cbd12422132806
Closes-Bug: #1378866
Add Juno release milestone

Change-Id: Iea584b00329d9474c14847db958f8743d4058525
Closes-Bug: #1378855
Merge "Add database relationship between router and ports"
Merge "Cisco N1kv: Remove vmnetwork delete REST call on last port delete"
Merge "Add Juno release milestone"