ft: Closing windows asks to save queries before closing the window.

fix: closetab did incorrectly close when cancel was choosen.

pglab/ManagedPage.h

@@ -0,0 +1,17 @@
+#ifndef MANAGEDPAGE_H
+#define MANAGEDPAGE_H
+
+#include <QWidget>
+
+class ManagedPage: public QWidget
+{
+	Q_OBJECT
+public:
+	using QWidget::QWidget;
+
+	virtual ~ManagedPage() {}
+
+	virtual bool CanClose(bool prompt_user) = 0;
+};
+
+#endif // MANAGEDPAGE_H