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/fib-entry.hpp b/daemon/table/fib-entry.hpp
index 67f5056..20d0206 100644
--- a/daemon/table/fib-entry.hpp
+++ b/daemon/table/fib-entry.hpp
@@ -9,7 +9,7 @@
 
 #include "fib-nexthop.hpp"
 
-namespace ndn {
+namespace nfd {
 namespace fib {
 
 /** \class NextHopList
@@ -71,6 +71,6 @@
 
 
 } // namespace fib
-} // namespace ndn
+} // namespace nfd
 
 #endif // NFD_TABLE_FIB_ENTRY_HPP