Add neighbor lifecycle management.

 * Made PIMNeighbor mostly immutable (apart from updatable timestamp)
 * Equals and hashCode for PIMNeighbor
 * Remove neighbor when we see a HELLO with holdTime==0
 * Periodic task to time out neighbors who haven't sent a HELLO in a while
 * Added a CLI command to view PIM neighbors

Change-Id: I59e52a847f7abcb8e9ac660c2cccace53e46867b
diff --git a/apps/pim/src/main/resources/OSGI-INF/blueprint/shell-config.xml b/apps/pim/src/main/resources/OSGI-INF/blueprint/shell-config.xml
index 780ad9f..012760d 100644
--- a/apps/pim/src/main/resources/OSGI-INF/blueprint/shell-config.xml
+++ b/apps/pim/src/main/resources/OSGI-INF/blueprint/shell-config.xml
@@ -19,6 +19,9 @@
         <command>
             <action class="org.onosproject.pim.cli.PimInterfacesListCommand"/>
         </command>
+        <command>
+            <action class="org.onosproject.pim.cli.PimNeighborsListCommand"/>
+        </command>
     </command-bundle>
 
 </blueprint>