Add intents and logging to Event History app

Also fixed overshadowing of hosts cli flag

Change-Id: I09c12a6cc4ab431a948905e8c1a76c2a9998aa75
diff --git a/apps/events/src/main/java/org/onosproject/events/EventHistoryManager.java b/apps/events/src/main/java/org/onosproject/events/EventHistoryManager.java
index b5ee316..0bdd94b 100644
--- a/apps/events/src/main/java/org/onosproject/events/EventHistoryManager.java
+++ b/apps/events/src/main/java/org/onosproject/events/EventHistoryManager.java
@@ -44,6 +44,7 @@
 import org.onosproject.net.device.DeviceService;
 import org.onosproject.net.edge.EdgePortService;
 import org.onosproject.net.host.HostService;
+import org.onosproject.net.intent.IntentService;
 import org.onosproject.net.link.LinkService;
 import org.onosproject.net.topology.TopologyService;
 import org.slf4j.Logger;
@@ -84,6 +85,9 @@
     protected EdgePortService edgeService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected IntentService intentService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected NetworkConfigService netcfgService;
 
     @Property(name = "excludeStatsEvent", boolValue = true,
@@ -127,6 +131,7 @@
                  .addListener(hostService, this::addEvent)
                  .addListener(clusterService, this::addEvent)
                  .addListener(edgeService, this::addEvent)
+                 .addListener(intentService, this::addEvent)
                  .addListener(netcfgService, this::addEvent);
 
         log.info("Started");
@@ -164,6 +169,9 @@
     }
 
     private void addEvent(Event<?, ?> event) {
+        if (log.isTraceEnabled()) {
+            log.trace(event.toString());
+        }
         history.offer(event);
     }