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/fw/forwarder.hpp b/daemon/fw/forwarder.hpp
index 3f9947a..6395f29 100644
--- a/daemon/fw/forwarder.hpp
+++ b/daemon/fw/forwarder.hpp
@@ -10,7 +10,7 @@
 #include "common.hpp"
 #include "face/face.hpp"
 
-namespace ndn {
+namespace nfd {
 
 /**
  * Forwarder is the main class of NFD.