encoding: change Block::fromBuffer return type

Block::fromBuffer is changed from taking constructed Block as output parameter
to returning the constructed Block as part of returned tuple.

Old API becomes deprecated.

refs #2553

Change-Id: I64610353b8c0780ee09ebe9089c539fa27506a5e
diff --git a/src/transport/stream-transport.hpp b/src/transport/stream-transport.hpp
index b4e3d09..737842c 100644
--- a/src/transport/stream-transport.hpp
+++ b/src/transport/stream-transport.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2014 Regents of the University of California.
+ * Copyright (c) 2013-2015 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -204,16 +204,16 @@
   bool
   processAll(uint8_t* buffer, size_t& offset, size_t nBytesAvailable)
   {
-    while (offset < nBytesAvailable)
-      {
-        Block element;
-        bool ok = Block::fromBuffer(buffer + offset, nBytesAvailable - offset, element);
-        if (!ok)
-          return false;
+    while (offset < nBytesAvailable) {
+      bool isOk = false;
+      Block element;
+      std::tie(isOk, element) = Block::fromBuffer(buffer + offset, nBytesAvailable - offset);
+      if (!isOk)
+        return false;
 
-        m_transport.receive(element);
-        offset += element.size();
-      }
+      m_transport.receive(element);
+      offset += element.size();
+    }
     return true;
   }