src: Remove unnecessary uses of boost::cref in make_shared and replace boost::cref/boost::ref with just cref/ref

In some cases, due to argument-dependent lookup, it is necessary to use
ndn::ref, instead of just ref.

Change-Id: I682180a007609535855f77511b49622154ad4f11
Refs: #1591
diff --git a/daemon/face/udp-factory.cpp b/daemon/face/udp-factory.cpp
index e97e9bb..470fd5e 100644
--- a/daemon/face/udp-factory.cpp
+++ b/daemon/face/udp-factory.cpp
@@ -148,8 +148,7 @@
                 "create a multicast face");
   }
 
-  channel = make_shared<UdpChannel>(boost::cref(endpoint),
-                                    timeout);
+  channel = make_shared<UdpChannel>(endpoint, timeout);
   m_channels[endpoint] = channel;
   prohibitEndpoint(endpoint);
 
@@ -208,7 +207,7 @@
   }
 
   shared_ptr<ip::udp::socket> clientSocket =
-    make_shared<ip::udp::socket>(boost::ref(getGlobalIoService()));
+    make_shared<ip::udp::socket>(ref(getGlobalIoService()));
 
   clientSocket->open(multicastEndpoint.protocol());
 
@@ -249,7 +248,7 @@
 
   clientSocket->set_option(ip::multicast::enable_loopback(false));
 
-  multicastFace = make_shared<MulticastUdpFace>(boost::cref(clientSocket), localEndpoint);
+  multicastFace = make_shared<MulticastUdpFace>(clientSocket, localEndpoint);
   multicastFace->onFail += bind(&UdpFactory::afterFaceFailed, this, localEndpoint);
 
   m_multicastFaces[localEndpoint] = multicastFace;
@@ -326,8 +325,8 @@
       return;
     }
   }
-  onConnectFailed("No channels available to connect to "
-                  + boost::lexical_cast<std::string>(endpoint));
+  onConnectFailed("No channels available to connect to " +
+                  boost::lexical_cast<std::string>(endpoint));
 }
 
 shared_ptr<UdpChannel>