face+mgmt: simplify factories and FaceManager using C++11 features

Change-Id: I113a4c15ef82bff705f61f31b170f49727bc3794
Refs: #3258
diff --git a/daemon/face/websocket-channel.hpp b/daemon/face/websocket-channel.hpp
index f560ab3..027085c 100644
--- a/daemon/face/websocket-channel.hpp
+++ b/daemon/face/websocket-channel.hpp
@@ -31,6 +31,10 @@
 
 namespace nfd {
 
+namespace websocket {
+typedef boost::asio::ip::tcp::endpoint Endpoint;
+} // namespace websocket
+
 /**
  * \brief Class implementing WebSocket-based channel to create faces
  */