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/device/DeviceEvent.java b/net/api/src/main/java/org/onlab/onos/net/device/DeviceEvent.java
new file mode 100644
index 0000000..d82ae42
--- /dev/null
+++ b/net/api/src/main/java/org/onlab/onos/net/device/DeviceEvent.java
@@ -0,0 +1,56 @@
+package org.onlab.onos.net.device;
+
+import org.onlab.onos.event.AbstractEvent;
+import org.onlab.onos.net.Device;
+
+/**
+ * Describes infrastructure device event.
+ */
+public class DeviceEvent extends AbstractEvent<DeviceEvent.Type, Device> {
+
+    /**
+     * Type of device events.
+     */
+    public enum Type {
+        /** Signifies that a new device has been detected. */
+        DEVICE_ADDED,
+
+        /** Signifies that a device has been removed. */
+        DEVICE_REMOVED,
+
+        /** Signifies that a device has been administratively suspended. */
+        DEVICE_SUSPENDED,
+
+        /** Signifies that a device has come online or has gone offline. */
+        DEVICE_AVAILABILITY_CHANGED,
+
+        /**
+         * Signifies that the current controller instance relationship has
+         * changed with respect to a device.
+         */
+        DEVICE_MASTERSHIP_CHANGED
+    }
+
+    /**
+     * Creates an event of a given type and for the specified subject and the
+     * current time.
+     *
+     * @param type    event type
+     * @param subject event subject
+     */
+    public DeviceEvent(Type type, Device subject) {
+        super(type, subject);
+    }
+
+    /**
+     * Creates an event of a given type and for the specified subject and time.
+     *
+     * @param type    event type
+     * @param subject event subject
+     * @param time    occurrence time
+     */
+    public DeviceEvent(Type type, Device subject, long time) {
+        super(type, subject, time);
+    }
+
+}