Additions to southbound API interfaces

added API interfaces for topology

added rough API interfaces for flow

Change-Id: I84ee2b70dd33dcbca98c1863e7f1766cc02642c5
diff --git a/net/api/src/main/java/net/onrc/onos/api/topology/TopologyProviderBroker.java b/net/api/src/main/java/net/onrc/onos/api/topology/TopologyProviderBroker.java
new file mode 100644
index 0000000..207f33a
--- /dev/null
+++ b/net/api/src/main/java/net/onrc/onos/api/topology/TopologyProviderBroker.java
@@ -0,0 +1,10 @@
+package net.onrc.onos.api.topology;
+
+import net.onrc.onos.api.ProviderBroker;
+
+/**
+ * Abstraction of a network topology provider brokerage.
+ */
+public interface TopologyProviderBroker extends
+        ProviderBroker<TopologyProvider, TopologyProviderService> {
+}