Added support for IPv6 addresses to class IpAddress:

 - For some of the methods, the IP Version needs to be specified by the
   caller. This applies to the IpPrefix API as well.
 - For now, everywhere IpAddress is used and the IP version has to be
   explicitly specified by the caller, we assume/specify IPv4.
 - Added unit test for class IpAddress: for both IPv4 and IPv6 addresses.
diff --git a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/bgp/BgpSession.java b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/bgp/BgpSession.java
index af67f1a..901ac90 100644
--- a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/bgp/BgpSession.java
+++ b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/bgp/BgpSession.java
@@ -246,11 +246,13 @@
         InetAddress inetAddr;
         if (localAddress instanceof InetSocketAddress) {
             inetAddr = ((InetSocketAddress) localAddress).getAddress();
-            localIp4Address = IpAddress.valueOf(inetAddr.getAddress());
+            localIp4Address = IpAddress.valueOf(IpAddress.Version.INET,
+                                                inetAddr.getAddress());
         }
         if (remoteAddress instanceof InetSocketAddress) {
             inetAddr = ((InetSocketAddress) remoteAddress).getAddress();
-            remoteIp4Address = IpAddress.valueOf(inetAddr.getAddress());
+            remoteIp4Address = IpAddress.valueOf(IpAddress.Version.INET,
+                                                 inetAddr.getAddress());
         }
 
         log.debug("BGP Session Connected from {} on {}",
diff --git a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/bgp/BgpSessionManager.java b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/bgp/BgpSessionManager.java
index 1b5dfb5..247c95f 100644
--- a/apps/sdnip/src/main/java/org/onlab/onos/sdnip/bgp/BgpSessionManager.java
+++ b/apps/sdnip/src/main/java/org/onlab/onos/sdnip/bgp/BgpSessionManager.java
@@ -105,7 +105,8 @@
         if (bgpSession.getLocalAddress() instanceof InetSocketAddress) {
             InetAddress inetAddr =
                 ((InetSocketAddress) bgpSession.getLocalAddress()).getAddress();
-            IpAddress ip4Address = IpAddress.valueOf(inetAddr.getAddress());
+            IpAddress ip4Address = IpAddress.valueOf(IpAddress.Version.INET,
+                                                     inetAddr.getAddress());
             updateMyBgpId(ip4Address);
         }
         return true;