Added Host related memos.

Change-Id: Idbbce6a72b6f7fecc6691f2af68f4ce40b58ca34

@@ -20,6 +20,7 @@ public class DefaultHost extends AbstractElement implements Host {
     private final MacAddress mac;
     private final VlanId vlan;
     private final HostLocation location;
+    // FIXME: should be IpAddress
     private final Set<IpPrefix> ips;
 
     /**

@@ -38,6 +38,7 @@ public interface Host extends Element {
      *
      * @return set of IP addresses; empty if no IP address is bound
      */
+    // FIXME: Switch to IpAddress
     Set<IpPrefix> ipAddresses();
 
     /**

@@ -37,6 +37,7 @@ public interface HostDescription extends Description {
      *
      * @return host IP address
      */
+    // FIXME: Switch to IpAddress
     IpPrefix ipAddress();
 
 }

@@ -29,6 +29,7 @@ public interface HostStore extends Store<HostEvent, HostStoreDelegate> {
     HostEvent createOrUpdateHost(ProviderId providerId, HostId hostId,
                                  HostDescription hostDescription);
 
+    // FIXME: API to remove only IpAddress is missing
     /**
      * Removes the specified host from the inventory.
      *
@@ -81,6 +82,7 @@ public interface HostStore extends Store<HostEvent, HostStoreDelegate> {
      * @param ip ip address
      * @return set of hosts with the given IP
      */
+    // FIXME: Switch to IpAddress
     Set<Host> getHosts(IpPrefix ip);
 
     /**

@@ -17,6 +17,7 @@ import com.google.common.base.MoreObjects;
 public class PortAddresses {
 
     private final ConnectPoint connectPoint;
+    // TODO: Should this be IpAddress or IpPrefix?
     private final Set<IpPrefix> ipAddresses;
     private final MacAddress macAddress;
 

@@ -43,6 +43,7 @@ import java.util.concurrent.ConcurrentHashMap;
 import static org.onlab.onos.net.host.HostEvent.Type.*;
 import static org.slf4j.LoggerFactory.getLogger;
 
+//TODO: multi-provider, annotation not supported.
 /**
  * Manages inventory of end-station hosts in distributed data store
  * that uses optimistic replication and gossip based techniques.

@@ -35,6 +35,7 @@ import java.util.concurrent.ConcurrentHashMap;
 import static org.onlab.onos.net.host.HostEvent.Type.*;
 import static org.slf4j.LoggerFactory.getLogger;
 
+// TODO: multi-provider, annotation not supported.
 /**
  * Manages inventory of end-station hosts using trivial in-memory
  * implementation.