NFD+model+apps+helper+tests: Upgrade NFD and related changes

Based on NFD:commit:2fc649bfc67b93b4191cfbee5bcd70330bfb48f0 (version 0.3.4)

Change-Id: I89f5182600467171797af4f8f83e1edffe14ad95
Refs: #3125
diff --git a/model/ndn-l3-protocol.cpp b/model/ndn-l3-protocol.cpp
index d45e84a..ad9c0d7 100644
--- a/model/ndn-l3-protocol.cpp
+++ b/model/ndn-l3-protocol.cpp
@@ -111,9 +111,9 @@
       "  strategy_choice\n"
       "  {\n"
       "    /               /localhost/nfd/strategy/best-route\n"
-      "    /localhost      /localhost/nfd/strategy/broadcast\n"
+      "    /localhost      /localhost/nfd/strategy/multicast\n"
       "    /localhost/nfd  /localhost/nfd/strategy/best-route\n"
-      "    /ndn/broadcast  /localhost/nfd/strategy/broadcast\n"
+      "    /ndn/multicast  /localhost/nfd/strategy/multicast\n"
       "  }\n"
       "}\n"
       "\n"
@@ -325,15 +325,15 @@
   m_impl->m_forwarder->addFace(face);
 
   // Connect Signals to TraceSource
-  face->onReceiveInterest +=
-    [this, face](const Interest& interest) { this->m_inInterests(interest, *face); };
+  face->onReceiveInterest.connect
+    ([this, face](const Interest& interest) { this->m_inInterests(interest, *face); });
 
-  face->onSendInterest +=
-    [this, face](const Interest& interest) { this->m_outInterests(interest, *face); };
+  face->onSendInterest.connect
+    ([this, face](const Interest& interest) { this->m_outInterests(interest, *face); });
 
-  face->onReceiveData += [this, face](const Data& data) { this->m_inData(data, *face); };
+  face->onReceiveData.connect([this, face](const Data& data) { this->m_inData(data, *face); });
 
-  face->onSendData += [this, face](const Data& data) { this->m_outData(data, *face); };
+  face->onSendData.connect([this, face](const Data& data) { this->m_outData(data, *face); });
 
   return face->getId();
 }