nexus: Switch controllers to use abstracted properties and refactor command protocol

Also fixes a select() bug and removes debugging

Signed-off-by: San Mehat <san@google.com>

nexus: fix whitespace
diff --git a/nexus/OpenVpnController.h b/nexus/OpenVpnController.h
index b321029..439e18a 100644
--- a/nexus/OpenVpnController.h
+++ b/nexus/OpenVpnController.h
@@ -31,6 +31,8 @@
 
     int start();
     int stop();
+
+private:
     int enable();
     int disable();
 };