logic: multithreaded parsing

* modified the TaskParseCxx to be able to run multiple times in parallel
* made FileRegister threadsafe and changed a lot of its mechanisms
* added TaskGroupParallel that runs all children in parallel
* added TaskParseWrapper that acts as a decorator to execute some code before and after parsing.
* implemented task setup in project with 4 parsing threads
* removed SimpleTask as it was only used as interface for the LambdaTask

src/lib/utility/scheduling/TaskGroupParallel.h

@@ -0,0 +1,30 @@
+#ifndef TASK_GROUP_PARALLEL_H
+#define TASK_GROUP_PARALLEL_H
+
+#include "utility/scheduling/TaskGroup.h"
+#include <mutex>
+
+class TaskGroupParallel
+	: public TaskGroup
+{
+public:
+	TaskGroupParallel();
+	virtual ~TaskGroupParallel();
+
+	virtual void enter();
+	virtual TaskState update();
+	virtual void exit();
+
+	virtual void interrupt();
+	virtual void revert();
+
+private:
+	void processTask(std::shared_ptr<Task> task);
+
+	volatile bool m_interrupt;
+	bool m_running;
+	volatile int m_activeTaskCount;
+	std::mutex m_activeTaskCountMutex;
+};
+
+#endif // TASK_GROUP_PARALLEL_H