Began integration with ONOS discovery code by implementing add switch and add link

Change-Id: I21426ea7031df20701d186cb2840a380fa334728

Made NetworkGraphModule to provide access to the global NetworkGraph instance

Change-Id: Ie2293b97f9fb6bdeaa5140c244a21c107d5e1ca7
diff --git a/src/main/resources/META-INF/services/net.floodlightcontroller.core.module.IFloodlightModule b/src/main/resources/META-INF/services/net.floodlightcontroller.core.module.IFloodlightModule
index dfd31ab..e796810 100644
--- a/src/main/resources/META-INF/services/net.floodlightcontroller.core.module.IFloodlightModule
+++ b/src/main/resources/META-INF/services/net.floodlightcontroller.core.module.IFloodlightModule
@@ -1,5 +1,5 @@
 net.floodlightcontroller.core.FloodlightProvider
-net.onrc.onos.ofcontroller.floodlightlistener.NetworkGraphPublisher
+net.onrc.onos.ofcontroller.floodlightlistener.RCNetworkGraphPublisher
 net.onrc.onos.ofcontroller.linkdiscovery.internal.LinkDiscoveryManager
 net.floodlightcontroller.topology.TopologyManager
 net.floodlightcontroller.forwarding.Forwarding
@@ -21,3 +21,4 @@
 net.onrc.onos.ofcontroller.proxyarp.ProxyArpManager
 net.onrc.onos.ofcontroller.core.config.DefaultConfiguration
 net.onrc.onos.ofcontroller.devicemanager.OnosDeviceManager
+net.onrc.onos.ofcontroller.networkgraph.NetworkGraphModule