+ fix warning of unused variable

+ when clearing scene graph then also empty internal lists
+ whitespace changes

src/Gui/DocumentRecovery.cpp

@@ -453,7 +453,7 @@ void DocumentRecovery::contextMenuEvent(QContextMenuEvent* ev)
     QList<QTreeWidgetItem*> items = d_ptr->ui.treeWidget->selectedItems();
     if (!items.isEmpty()) {
         QMenu menu;
-        QAction* rem = menu.addAction(tr("Delete"), this, SLOT(onDeleteSection()));
+        menu.addAction(tr("Delete"), this, SLOT(onDeleteSection()));
         menu.exec(ev->globalPos());
     }
 }