Created basic network graph objects, and implementation for the southbound API against the Ramcloud datastore

Change-Id: I2172dacb171f27ba2099ee5a52835030d2004689

Created basic objects and southbound API to build the network graph

Change-Id: I061efdf10e5e8549f7192844d10781dc28ee62d4

Added basic northbound get switch method on network graph

Change-Id: I4f2e4d4a4df00979abc927ef0772997dcdebc4e2
diff --git a/src/main/java/net/onrc/onos/ofcontroller/networkgraph/Device.java b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/Device.java
new file mode 100644
index 0000000..5124f82
--- /dev/null
+++ b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/Device.java
@@ -0,0 +1,16 @@
+package net.onrc.onos.ofcontroller.networkgraph;
+
+import java.net.InetAddress;
+import java.util.Collection;
+
+import net.floodlightcontroller.util.MACAddress;
+
+public interface Device {
+	public MACAddress getMacAddress();
+	
+	public Collection<InetAddress> getIpAddress();
+	
+	public Iterable<Port> getAttachmentPoints();
+	
+	public long getLastSeenTime();
+}