reimplementaion of fix for QColorDialog on macOS Sierra bug.

doesn't use destructor because destructor causes another crash.

YACReaderLibrary/add_label_dialog.h

@@ -0,0 +1,31 @@
+#ifndef ADD_LABEL_DIALOG_H
+#define ADD_LABEL_DIALOG_H
+
+#include <QtWidgets>
+
+#include "yacreader_global.h"
+
+class AddLabelDialog : public QDialog
+{
+    Q_OBJECT
+public:
+    explicit AddLabelDialog(QWidget *parent = 0);
+    YACReader::LabelColors selectedColor();
+    QString name();
+signals:
+
+public slots:
+    int exec();
+
+protected slots:
+    void validateName(const QString & name);
+
+protected:
+    QLineEdit * edit;
+    QListWidget * list;
+
+    QPushButton * acceptButton;
+    QPushButton * cancelButton;
+};
+
+#endif // ADD_LABEL_DIALOG_H