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/examples/1-sampler-sink/runExample1Sampler.cxx

@@ -13,7 +13,6 @@
  */
 
 #include <iostream>
-#include <csignal>
 
 #include "boost/program_options.hpp"
 
@@ -30,31 +29,10 @@
 
 using namespace boost::program_options;
 
-FairMQExample1Sampler sampler;
-
-static void s_signal_handler(int signal)
-{
-    LOG(INFO) << "Caught signal " << signal;
-
-    sampler.ChangeState("END");
-
-    LOG(INFO) << "Shutdown complete.";
-    exit(1);
-}
-
-static void s_catch_signals(void)
-{
-    struct sigaction action;
-    action.sa_handler = s_signal_handler;
-    action.sa_flags = 0;
-    sigemptyset(&action.sa_mask);
-    sigaction(SIGINT, &action, NULL);
-    sigaction(SIGTERM, &action, NULL);
-}
-
 int main(int argc, char** argv)
 {
-    s_catch_signals();
+    FairMQExample1Sampler sampler;
+    sampler.CatchSignals();
 
     FairMQProgOptions config;
 
@@ -100,18 +78,7 @@ int main(int argc, char** argv)
         sampler.WaitForEndOfState("INIT_TASK");
 
         sampler.ChangeState("RUN");
-        sampler.WaitForEndOfState("RUN");
-
-        sampler.ChangeState("STOP");
-
-        sampler.ChangeState("RESET_TASK");
-        sampler.WaitForEndOfState("RESET_TASK");
-
-        sampler.ChangeState("RESET_DEVICE");
-        sampler.WaitForEndOfState("RESET_DEVICE");
-
-        sampler.ChangeState("END");
-
+        sampler.InteractiveStateLoop();
     }
     catch (std::exception& e)
     {