minor cleanup: include orders, end comments etc.

- no code changes

src/qt/optionsdialog.h

@@ -7,10 +7,13 @@
 
 #include <QDialog>
 
-class QDataWidgetMapper;
 class OptionsModel;
 class QValidatedLineEdit;
 
+QT_BEGIN_NAMESPACE
+class QDataWidgetMapper;
+QT_END_NAMESPACE
+
 namespace Ui {
 class OptionsDialog;
 }