face: face refactoring completion

* delete old Face
* rename LpFace as Face
* eliminate LpFaceWrapper and use new Face

refs #3172

Change-Id: I08c3a5dfb4cc1b9834b30cccd9ab634535d0608c
diff --git a/daemon/face/channel.cpp b/daemon/face/channel.cpp
index d161504..65e0a25 100644
--- a/daemon/face/channel.cpp
+++ b/daemon/face/channel.cpp
@@ -1,11 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014  Regents of the University of California,
- *                     Arizona Board of Regents,
- *                     Colorado State University,
- *                     University Pierre & Marie Curie, Sorbonne University,
- *                     Washington University in St. Louis,
- *                     Beijing Institute of Technology
+ * Copyright (c) 2014-2015,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
@@ -20,7 +21,7 @@
  *
  * You should have received a copy of the GNU General Public License along with
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- **/
+ */
 
 #include "channel.hpp"
 
@@ -36,4 +37,17 @@
   m_uri = uri;
 }
 
+void
+connectFaceClosedSignal(Face& face, const std::function<void()>& f)
+{
+  using face::FaceState;
+
+  face.afterStateChange.connect(
+    [f] (FaceState oldState, FaceState newState) {
+      if (newState == FaceState::CLOSED) {
+        f();
+      }
+    });
+}
+
 } // namespace nfd