Add shared memory example

- Add shared memory example in examples/MQ/SharedMemory
 - Device/Task termination: try soft first, and abort if it fails
 - Interactive mode: prevent cin from blocking forever (poll)

fairmq/FairMQDevice.h

@@ -330,6 +330,9 @@ class FairMQDevice : public FairMQStateMachine, public FairMQConfigurable
     /// Signal handler
     void SignalHandler(int signal);
     bool fCatchingSignals;
+    bool fTerminated;
+    // Interactive state loop helper
+    std::atomic<bool> fRunning;
 };
 
 #endif /* FAIRMQDEVICE_H_ */