all: cleanup common.hpp and import typenames from ndn namespace.

This allows us to compile NFD in C++11 mode, making use of std::shared_ptr,
std::function, std::bind, etc. rather than their boost equivalents
(provided that ndn-cpp-dev is also compiled in C++11 mode). This is an
experimental feature and may not work properly.

Change-Id: I310529f78e1e428a8530b087983130d1ef3a9d88
diff --git a/tests/mgmt/config-file.cpp b/tests/mgmt/config-file.cpp
index df0d9c3..ff352d4 100644
--- a/tests/mgmt/config-file.cpp
+++ b/tests/mgmt/config-file.cpp
@@ -22,11 +22,12 @@
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
  **/
 
-
 #include "mgmt/config-file.hpp"
 
 #include "tests/test-common.hpp"
 
+#include <fstream>
+
 namespace nfd {
 namespace tests {