rename topology related objects: Device -> Host

- KVDevice to be renamed later.
- Use fully qualified name for topology's Host. (HostManager.java)

Change-Id: I1538f96d7ca93ca2197d23e5a69b85d284611412
diff --git a/src/main/java/net/onrc/onos/core/topology/SwitchImpl.java b/src/main/java/net/onrc/onos/core/topology/SwitchImpl.java
index 3e2b9aa..fdd37b3 100644
--- a/src/main/java/net/onrc/onos/core/topology/SwitchImpl.java
+++ b/src/main/java/net/onrc/onos/core/topology/SwitchImpl.java
@@ -117,18 +117,18 @@
     }
 
     @Override
-    public Collection<Device> getDevices() {
+    public Collection<Host> getHosts() {
         // TODO Should switch also store a list of attached devices to avoid
         // calculating this every time?
-        List<Device> devices = new ArrayList<Device>();
+        List<Host> hosts = new ArrayList<Host>();
 
         for (Port port : getPorts()) {
-            for (Device device : port.getDevices()) {
-                devices.add(device);
+            for (Host host : port.getHosts()) {
+                hosts.add(host);
             }
         }
 
-        return devices;
+        return hosts;
     }
 
     void replaceStringAttributes(SwitchEvent updated) {