src: Changing namespace ndn to namespace nfd

Also, this commit imports used classes from ::ndn namespace (from
NDN-CPP library) directly to ::nfd namespace.

refs: #1163

Change-Id: I9cc9d72e00af495b4ed0c84e6d418a7c9ba986cb
diff --git a/daemon/table/pit-face-record.hpp b/daemon/table/pit-face-record.hpp
index d2dfe2c..b51c0bc 100644
--- a/daemon/table/pit-face-record.hpp
+++ b/daemon/table/pit-face-record.hpp
@@ -10,7 +10,7 @@
 #include "face/face.hpp"
 #include "core/time.hpp"
 
-namespace ndn {
+namespace nfd {
 namespace pit {
 
 /** \class FaceRecord
@@ -78,6 +78,6 @@
 }
 
 } // namespace pit
-} // namespace ndn
+} // namespace nfd
 
 #endif // NFD_TABLE_PIT_FACE_RECORD_HPP