[AETHER-539] Fix for flowId computation

This patch includes:
- New methods in the PortNumber to take into account the port name
- PortCriterion uses the new toString method to avoid mismatch
  in the flowId computation
- The original toString() method is left unchanged to avoid
  disply issues of the ports with names

Change-Id: I392281b5eee160227886f9738fae97f237b1b04f
diff --git a/core/api/src/main/java/org/onosproject/net/flow/criteria/PortCriterion.java b/core/api/src/main/java/org/onosproject/net/flow/criteria/PortCriterion.java
index af0673b..a2c49a1 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/criteria/PortCriterion.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/criteria/PortCriterion.java
@@ -54,7 +54,7 @@
 
     @Override
     public String toString() {
-        return type().toString() + SEPARATOR + port;
+        return type().toString() + SEPARATOR + port.toStringWithoutName();
     }
 
     @Override