Update multi-part features (nanomsg) and various fixes

- Implement nanomsg multipart with MessagePack.
 - Use the MessagePack from FairSoft and handle not found case.
 - Update splitter, merger and proxy devices to handle multi-part.
 - Let FairMQParts.At() return pointer reference (can be used for moving).
 - Add missing const specifier in the message interface.
 - Add transmit kernel size setting to channels (ZMQ_SNDBUF).
 - Remove FairMQBuffer device.
 - Remove old multi-part methods from Tutorial3 example (to be replaced with Parts API).
 - Make callback mandatory for newMsg(data, size, callback).
 - Add missing <vector> include in FairMQSocket.

fairmq/nanomsg/FairMQSocketNN.h

@@ -15,6 +15,8 @@
 #ifndef FAIRMQSOCKETNN_H_
 #define FAIRMQSOCKETNN_H_
 
+#include <vector>
+
 #include <nanomsg/nn.h>
 #include <nanomsg/pipeline.h>
 #include <nanomsg/pubsub.h>
@@ -37,8 +39,11 @@ class FairMQSocketNN : public FairMQSocket
 
     virtual int Send(FairMQMessage* msg, const std::string& flag = "");
     virtual int Send(FairMQMessage* msg, const int flags = 0);
+    virtual int64_t Send(const std::vector<std::unique_ptr<FairMQMessage>>& msgVec);
+
     virtual int Receive(FairMQMessage* msg, const std::string& flag = "");
     virtual int Receive(FairMQMessage* msg, const int flags = 0);
+    virtual int64_t Receive(std::vector<std::unique_ptr<FairMQMessage>>& msgVec);
 
     virtual void* GetSocket() const;
     virtual int GetSocket(int nothing) const;