Add (optional) Google Protocol Buffers support (example in Tutorial 3).

To use protobuf, run cmake as follows:
cmake -DUSE_PROTOBUF=1 ..
For this, protobuf library has to be installed on the system.

Further changes:
Clean up splitter/merger: default are N-to-1-merger and 1-to-N-splitter.
Fix bug in nanomsg message deallocation.
Setup proper buffer sizes for nanomsg/zeromq via cmake/bash script.
chmod +x for start scripts.

fairmq/prototest/FairMQProtoSampler.h

@@ -0,0 +1,41 @@
+/**
+ * FairMQProtoSampler.h
+ *
+ * @since 2013-04-23
+ * @author D. Klein, A. Rybalchenko
+ */
+
+#ifndef FAIRMQPROTOSAMPLER_H_
+#define FAIRMQPROTOSAMPLER_H_
+
+#include <string>
+
+#include "FairMQDevice.h"
+
+class FairMQProtoSampler: public FairMQDevice
+{
+  public:
+    enum {
+      InputFile = FairMQDevice::Last,
+      EventRate,
+      EventSize,
+      Last
+    };
+    FairMQProtoSampler();
+    virtual ~FairMQProtoSampler();
+    void Log(int intervalInMs);
+    void ResetEventCounter();
+    virtual void SetProperty(const int key, const string& value, const int slot = 0);
+    virtual string GetProperty(const int key, const string& default_ = "", const int slot = 0);
+    virtual void SetProperty(const int key, const int value, const int slot = 0);
+    virtual int GetProperty(const int key, const int default_ = 0, const int slot = 0);
+
+  protected:
+    int fEventSize;
+    int fEventRate;
+    int fEventCounter;
+    virtual void Init();
+    virtual void Run();
+};
+
+#endif /* FAIRMQPROTOSAMPLER_H_ */