Sketching SB & NB API.
Modified onos-of-api pom to subsume openflowj loxi-generated stuff.
diff --git a/net/api/src/main/java/org/onlab/onos/net/host/HostProviderService.java b/net/api/src/main/java/org/onlab/onos/net/host/HostProviderService.java
index 4d5d470..c66054f 100644
--- a/net/api/src/main/java/org/onlab/onos/net/host/HostProviderService.java
+++ b/net/api/src/main/java/org/onlab/onos/net/host/HostProviderService.java
@@ -1,12 +1,25 @@
 package org.onlab.onos.net.host;
 
-import org.onlab.onos.net.ProviderService;
+import org.onlab.onos.provider.ProviderService;
 
 /**
  * Means of conveying host information to the core.
  */
 public interface HostProviderService extends ProviderService {
 
+    /**
+     * Notifies the core when a host has been detected on a network along with
+     * information that identifies the hoot location.
+     *
+     * @param hostDescription description of host and its location
+     */
     void hostDetected(HostDescription hostDescription);
 
+    /**
+     * Notifies the core when a host is no longer detected on a network.
+     *
+     * @param hostDescription description of host
+     */
+    void hostNotDetected(HostDescription hostDescription);
+
 }