Several FairMQ fixes and improvements:

- FairMQ: add possibility to poll on multiple channels.
- FairMQ: include command channel when polling on blocking calls (for unblocking without termination).
- FairMQ: move signal handler inside of FairMQDevice class (call FairMQDevice::CatchSignals() in the main function).
- FairMQ: add 'bool CheckCurrentState(statename)' (instead of 'GetCurrentState() == statename' that cannot be thread safe).
- FairMQDevice: add 'InteractiveStateLoop()' method that can be used to change states from the command line.
- FairMQDevice: add automatic transition to IDLE state if Run() exits without an external event.
- FairMQDevice: implement device reset.
- FairMQDevice: use unordered_map for device channels.
- FairMQChannel: improve address validation for channels.
- FairMQChannel: add ExpectsAnotherPart() method to check if another msg part is expected (old approach still works).
- FairMQ: remove invalid transition from the run files.
- FairMQFileSink: disable ROOT termination signal handler.
- Tutorial3: spawn xterm windows from start scripts without overlapping for better visibility.
- FairMQ Examples: update protobuf test and move its files to a common directory.
- FairMQStateMachine: improve feedback on invalid transitions (more readable).

fairmq/FairMQPoller.h

@@ -15,12 +15,16 @@
 #ifndef FAIRMQPOLLER_H_
 #define FAIRMQPOLLER_H_
 
+#include <string>
+
 class FairMQPoller
 {
   public:
-    virtual void Poll(int timeout) = 0;
-    virtual bool CheckInput(int index) = 0;
-    virtual bool CheckOutput(int index) = 0;
+    virtual void Poll(const int timeout) = 0;
+    virtual bool CheckInput(const int index) = 0;
+    virtual bool CheckOutput(const int index) = 0;
+    virtual bool CheckInput(const std::string channelKey, const int index) = 0;
+    virtual bool CheckOutput(const std::string channelKey, const int index) = 0;
 
     virtual ~FairMQPoller() {};
 };