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-entry.hpp b/daemon/table/pit-entry.hpp
index 97de5e2..00e8a79 100644
--- a/daemon/table/pit-entry.hpp
+++ b/daemon/table/pit-entry.hpp
@@ -10,7 +10,7 @@
 #include "pit-in-record.hpp"
 #include "pit-out-record.hpp"
 
-namespace ndn {
+namespace nfd {
 namespace pit {
 
 /** \class InRecordCollection
@@ -88,6 +88,6 @@
 }
 
 } // namespace pit
-} // namespace ndn
+} // namespace nfd
 
 #endif // NFD_TABLE_PIT_ENTRY_HPP