In vnet CLI, separates virutal port creation and binding operations.
Original usage with specifiying a phyiscal port is also in supporting.

Changes.
1. vnet-create-port allow to create virtual port
   without a specific virtual port
2. vnet-bind-port command is added to newly bind or to update
3. Virtual binding point is changed from Port to ConnectPoint.

Change-Id: I4c8f9a2b9b2786ba519ead3559d7f005390fee86
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/VirtualNetworkIntentCompiler.java b/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/VirtualNetworkIntentCompiler.java
index 8c04c6a..5eac0d4 100644
--- a/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/VirtualNetworkIntentCompiler.java
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/VirtualNetworkIntentCompiler.java
@@ -202,7 +202,7 @@
         for (VirtualPort port : ports) {
             if (port.element().id().equals(virtualCp.elementId()) &&
                     port.number().equals(virtualCp.port())) {
-                return new ConnectPoint(port.realizedBy().element().id(), port.realizedBy().number());
+                return new ConnectPoint(port.realizedBy().deviceId(), port.realizedBy().port());
             }
         }
         return null;