Work toward common IP address classes.

 * Updated classes PortAddresses (in core/api) and Interface (in sdnip)
   to use class InterfaceIpAddress instead of IpPrefix
 * Updated corresponding unit tests and relevant code
 * Minor refactoring inside ProxyArpManager to simplify some of the
   logic and usage related to PortAddresses. Also, renamed
   method findOutsidePortInSubnet() to findPortInSubnet() and updated
   its implementation to reflect better its usage.
diff --git a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/PeerConnectivityManagerTest.java b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/PeerConnectivityManagerTest.java
index e3e4896..832989f 100644
--- a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/PeerConnectivityManagerTest.java
+++ b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/PeerConnectivityManagerTest.java
@@ -31,6 +31,7 @@
 import org.onlab.onos.net.flow.DefaultTrafficTreatment;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
+import org.onlab.onos.net.host.InterfaceIpAddress;
 import org.onlab.onos.net.intent.IntentService;
 import org.onlab.onos.net.intent.PointToPointIntent;
 import org.onlab.onos.sdnip.bgp.BgpConstants;
@@ -175,14 +176,20 @@
         configuredInterfaces = new HashMap<>();
 
         String interfaceSw1Eth1 = "s1-eth1";
+        InterfaceIpAddress ia1 =
+            new InterfaceIpAddress(IpAddress.valueOf("192.168.10.1"),
+                                   IpPrefix.valueOf("192.168.10.0/24"));
         Interface intfsw1eth1 = new Interface(s1Eth1,
-                Collections.singleton(IpPrefix.valueOf("192.168.10.0/24")),
+                Collections.singleton(ia1),
                 MacAddress.valueOf("00:00:00:00:00:01"));
 
         configuredInterfaces.put(interfaceSw1Eth1, intfsw1eth1);
         String interfaceSw2Eth1 = "s2-eth1";
+        InterfaceIpAddress ia2 =
+            new InterfaceIpAddress(IpAddress.valueOf("192.168.20.2"),
+                                   IpPrefix.valueOf("192.168.20.0/24"));
         Interface intfsw2eth1 = new Interface(s2Eth1,
-                Collections.singleton(IpPrefix.valueOf("192.168.20.0/24")),
+                Collections.singleton(ia2),
                 MacAddress.valueOf("00:00:00:00:00:02"));
         configuredInterfaces.put(interfaceSw2Eth1, intfsw2eth1);