CORD-512 Support vSG <-> vRouter default route

- Support multiple subnets per port. getIpPort() will only return the first non-/32 and non-/0 subnet
    /32 is used as vSG subnet
    /0 is used as default gateway
- Support multiple L3 unicast group on a single port
    Change the way to generate the group ID and group key
- Special case for 0.0.0.0 host. Push a /0 to IP table instead of /32
- Implement vRouterConfig
    Put VR MAC to TMAC table of all leaves when config added
        When processEthDst see PortNumber.ANY in key, match ETH_DST only
- For OFDPA, wipe existing instruction before sending to controller
    So packet that misses L3 unicast table won't be sent to controller twice
- For SpringOpenTTP, pop VLAN before sending to controller
- Move several constant definitions to SegmentRoutingService
- Add minimum priority for IP rules such that /0 won't collide with zero priority default rules
- Update the config sample
    Use VLAN=-1 for hosts
    Add example for default route

Change-Id: Id751697ce36a7e5c13b3859350ff21b585c38525
diff --git a/pom.xml b/pom.xml
index 5562b9f..68777ef 100644
--- a/pom.xml
+++ b/pom.xml
@@ -97,6 +97,14 @@
             <artifactId>onlab-junit</artifactId>
             <scope>test</scope>
         </dependency>
+
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-api</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+            <classifier>tests</classifier>
+        </dependency>
     </dependencies>
 
     <build>