Added a QUndoStack and made it accessible for UIs.

genericcore.h

@@ -3,6 +3,7 @@
 
 #include <QObject>
 
+class QUndoStack;
 class QAbstractItemModel;
 class QString;
 
@@ -21,12 +22,14 @@ class GenericCore : public QObject {
   bool isApplicationUpdateAvailable();
   void triggerApplicationUpdate();
 
+  std::shared_ptr<QUndoStack> getModUndoStack() const;
   std::shared_ptr<QAbstractItemModel> getModel() const;
 
  signals:
   void displayStatusMessage(QString message);
 
  private:
+  std::shared_ptr<QUndoStack> m_modelUndoStack;
   std::shared_ptr<TableModel> m_mainModel;
 
   void setupModels();