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/cs-entry.hpp b/daemon/table/cs-entry.hpp
index 1726d87..2502105 100644
--- a/daemon/table/cs-entry.hpp
+++ b/daemon/table/cs-entry.hpp
@@ -9,7 +9,7 @@
 
 #include "common.hpp"
 
-namespace ndn {
+namespace nfd {
 namespace cs {
 
 /** \class Entry
@@ -21,6 +21,6 @@
 };
 
 } // namespace cs
-} // namespace ndn
+} // namespace nfd
 
 #endif // NFD_TABLE_CS_ENTRY_HPP