plugins/ip-faces: Initial implementation of UdpFace

Refs #1006 (http://redmine.named-data.net/)
diff --git a/model/ndn-l3-protocol.cc b/model/ndn-l3-protocol.cc
index e89c9ea..0c0332f 100644
--- a/model/ndn-l3-protocol.cc
+++ b/model/ndn-l3-protocol.cc
@@ -49,6 +49,7 @@
 namespace ndn {
 
 const uint16_t L3Protocol::ETHERNET_FRAME_TYPE = 0x7777;
+const uint16_t L3Protocol::IP_STACK_PORT = 9695;
 
 NS_OBJECT_ENSURE_REGISTERED (L3Protocol);