Change namespace of DummyClientFace, Signal, Segmenter, SegmentFetcher

refs #3940

Change-Id: Ia3c9b4adcca9ff79a14be705ca9da525914f3dff
diff --git a/src/hello-protocol.hpp b/src/hello-protocol.hpp
index a50c2b5..9ff1335 100644
--- a/src/hello-protocol.hpp
+++ b/src/hello-protocol.hpp
@@ -83,7 +83,7 @@
   void
   processInterest(const ndn::Name& name, const ndn::Interest& interest);
 
-  ndn::util::Signal<HelloProtocol, Statistics::PacketType> hpIncrementSignal;
+  ndn::signal::Signal<HelloProtocol, Statistics::PacketType> hpIncrementSignal;
 
 private:
   /*! \brief Try to contact a neighbor via Hello protocol again
@@ -126,7 +126,7 @@
   static inline const std::string INFO_COMPONENT{"INFO"};
   static inline const std::string NLSR_COMPONENT{"nlsr"};
 
-  ndn::util::Signal<HelloProtocol, const ndn::Name&> onInitialHelloDataValidated;
+  ndn::signal::Signal<HelloProtocol, const ndn::Name&> onInitialHelloDataValidated;
 
 private:
   ndn::Face& m_face;