Enable new callback API

- OnData() channel data handler.
 - ConditionalRun() for devices without incoming data.
 - Header file with common main(), to be extended with getDevice/addCustomOptions.
 - Update examples (MQ/Tutorial3) to use the new API and config.
 - NewSimpleMessage() for simpler creation of small messages (additional copy).
 - Replace SetProperty/GetProperty with fConfig access.
 - Runtime configurable channel names for common devices.
 - Configurable logging interval per channel.
 - FairMQMultiplier for distributing same data to multiple outputs.
 - Cleanup state machine messages.
 - Cmd option to toggle signal handling.
 - Simpler API for send/receive timeouts.
 - Enable --log-to-file.
 - Fix coverity issues, warnings.
 - Various code cleanup and minor tweaks.

examples/MQ/4-copypush/FairMQExample4Sampler.h

@@ -15,10 +15,10 @@
 #ifndef FAIRMQEXAMPLE4SAMPLER_H_
 #define FAIRMQEXAMPLE4SAMPLER_H_
 
-#include <string>
-
 #include "FairMQDevice.h"
 
+#include <stdint.h> // uint64_t
+
 class FairMQExample4Sampler : public FairMQDevice
 {
   public:
@@ -26,7 +26,11 @@ class FairMQExample4Sampler : public FairMQDevice
     virtual ~FairMQExample4Sampler();
 
   protected:
-    virtual void Run();
+    virtual void InitTask();
+    virtual bool ConditionalRun();
+
+    int fNumDataChannels;
+    uint64_t fCounter;
 };
 
 #endif /* FAIRMQEXAMPLE4SAMPLER_H_ */