nexus: Rename onInterfaceStarted -> onInterfaceConnected and add Dhcp start/stop control

Signed-off-by: San Mehat <san@google.com>
diff --git a/nexus/IControllerHandler.h b/nexus/IControllerHandler.h
index 92d015f..f7be39c 100644
--- a/nexus/IControllerHandler.h
+++ b/nexus/IControllerHandler.h
@@ -22,8 +22,8 @@
 
 class IControllerHandler {
 public:
-    virtual void onInterfaceStarted(Controller *c, const InterfaceConfig *cfg) = 0;
-    virtual void onInterfaceStopping(Controller *c, const char *name) = 0;
+    virtual void onInterfaceConnected(Controller *c, const InterfaceConfig *cfg) = 0;
+    virtual void onInterfaceDisconnected(Controller *c, const char *name) = 0;
 };
 
 #endif