Added some classes from a stackoverflow to utilize Qt's concurrency functions especially cancellable QFuture's

core/ControllableTask.h

@@ -0,0 +1,18 @@
+#ifndef CONTROLLABLETASK_H
+#define CONTROLLABLETASK_H
+/** From answer by Hatter
+ *
+ * https://stackoverflow.com/questions/5423058/qfuture-that-can-be-cancelled-and-report-progress
+ */
+
+#include "TaskControl.h"
+
+template <class T>
+class ControllableTask
+{
+public:
+	virtual ~ControllableTask() {}
+	virtual T run(TaskControl& control) = 0;
+};
+
+#endif // CONTROLLABLETASK_H