Implementing base support for TCP-style window-based limiting on per-FIB-prefix and per-face granularity

Currently, limits are supported only by ndn::fw::Limits forwarding
strategy and only at the very basic (not fully tested) level.
diff --git a/model/ndn-net-device-face.cc b/model/ndn-net-device-face.cc
index f5f38a0..7373ed8 100644
--- a/model/ndn-net-device-face.cc
+++ b/model/ndn-net-device-face.cc
@@ -38,6 +38,8 @@
 namespace ns3 {
 namespace ndn {
 
+NS_OBJECT_ENSURE_REGISTERED (NetDeviceFace);
+
 TypeId
 NetDeviceFace::GetTypeId ()
 {