add OuputDevice as singleton to manage output to statusbar,

QtMeshViewer/Header/OutputDevice.h

@@ -0,0 +1,27 @@
+#pragma once
+#include <QObject>
+
+class OutputDevice : public QObject
+{
+	Q_OBJECT
+
+private:
+	OutputDevice(QObject *parent = Q_NULLPTR) : QObject(parent) {};
+
+public:
+	OutputDevice(OutputDevice const&) = delete;
+	void operator=(OutputDevice const&) = delete;
+
+	~OutputDevice() {};
+
+	static OutputDevice* getInstance(QObject *parent = Q_NULLPTR) {
+		static OutputDevice* instance = new OutputDevice(parent);
+		return instance;
+	};
+
+	void print(QString message, int severity) { emit sendMessage(message, severity); };
+
+signals:
+	void sendMessage(QString message, int severity);
+
+};