Dual-homing probing improvements

(1) Active probing mechanism in the following two scenarios
    (1-1) Probe all ports on the pair device within the same vlan (excluding the pair port) when the 1st location of a host is learnt
    (1-2) Probe again when a device/port goes down and comes up again
    * Introduce HostLocationProvingService
        - DISCOVER mode: discover potential new locations
        - VERIFY mode: verify old locations
    * Can be enabled/disabled via component config
    * Improve HostHandlerTest to test the probing behavior

(2) Fix an issue that redirection flow doesn't get installed after device re-connects

(3) Temporarily fix a race condition in HostHandler by adding a little bit delay

Change-Id: I33d3fe94a6ca491a88b8e06f65bef11447ead0bf
diff --git a/core/net/src/main/java/org/onosproject/net/host/impl/HostManager.java b/core/net/src/main/java/org/onosproject/net/host/impl/HostManager.java
index b7a38e6..998f7df 100644
--- a/core/net/src/main/java/org/onosproject/net/host/impl/HostManager.java
+++ b/core/net/src/main/java/org/onosproject/net/host/impl/HostManager.java
@@ -29,6 +29,7 @@
 import org.onlab.packet.VlanId;
 import org.onlab.util.Tools;
 import org.onosproject.cfg.ComponentConfigService;
+import org.onosproject.net.host.HostLocationProbingService.ProbeMode;
 import org.onosproject.net.intf.Interface;
 import org.onosproject.net.intf.InterfaceService;
 import org.onosproject.net.HostLocation;
@@ -455,8 +456,8 @@
         }
 
         @Override
-        public MacAddress addPendingHostLocation(HostId hostId, HostLocation hostLocation) {
-            return store.addPendingHostLocation(hostId, hostLocation);
+        public MacAddress addPendingHostLocation(HostId hostId, ConnectPoint connectPoint, ProbeMode probeMode) {
+            return store.addPendingHostLocation(hostId, connectPoint, probeMode);
         }
 
         @Override