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/DeviceListener.java b/net/api/src/main/java/org/onlab/onos/net/device/DeviceListener.java
new file mode 100644
index 0000000..232fc95
--- /dev/null
+++ b/net/api/src/main/java/org/onlab/onos/net/device/DeviceListener.java
@@ -0,0 +1,7 @@
+package org.onlab.onos.net.device;
+
+/**
+ * Entity capable of receiving device related events.
+ */
+public interface DeviceListener {
+}