Add explicit configuration for enabling IPv6-related flow installation
(IPv6 Neighbor Discovery related flow mods).
The default configuration is false (disabled).

This fixes ONOS-1146

The configurable parameters are:

 tools/package/etc/org.onosproject.provider.host.impl.HostLocationProvider.cfg
  - Enable host removal on port/device down events.
    (NOTE: not IPv6 related, added for completeness)
    hostRemovalEnabled = true
  - Enable using IPv6 Neighbor Discovery by the Host Location Provider.
    ipv6NeighborDiscovery = false

 tools/package/etc/org.onosproject.proxyarp.ProxyArp.cfg
  - Enable IPv6 Neighbor Discovery.
    ipv6NeighborDiscovery = false

NOTE: The above IPv6-related configuration has drawbacks,
partially because of some PacketService-related side effects.
Currently, we don't support enabling ipv6NeighborDiscovery
in one of the configuration files, and disabling it in another.
Enabling ipv6NeighborDiscovery in one configuration file is
practically equivalent to enabling it in both places.

Change-Id: Ief558697d85c8dcffc8941c575d0bf7d1397d90d
diff --git a/apps/proxyarp/pom.xml b/apps/proxyarp/pom.xml
index 11723ab..e9c4333 100644
--- a/apps/proxyarp/pom.xml
+++ b/apps/proxyarp/pom.xml
@@ -31,4 +31,11 @@
 
     <description>ONOS simple proxy arp module</description>
 
+    <dependencies>
+        <dependency>
+            <groupId>org.osgi</groupId>
+            <artifactId>org.osgi.compendium</artifactId>
+        </dependency>
+    </dependencies>
+
 </project>