QWindow::alert(int msec) is a new slot in QWindow for 5.1 so it needs Q_REVISION(1)

    // All properties which are declared here are inherited by QQuickWindow and therefore available in QML.
    // So please think carefully about what it does to the QML namespace if you add any new ones,
    // particularly the possible meanings these names might have in any specializations of Window.
    // For example "state" (meaning windowState) is not a good property to declare, because it has
    // a different meaning in QQuickItem, and users will tend to assume it is the same for Window.

    // Any new properties which you add here MUST be versioned and MUST be documented both as
    // C++ properties in qwindow.cpp AND as QML properties in qquickwindow.cpp.
    // http://qt-project.org/doc/qt-5.0/qtqml/qtqml-cppintegration-definetypes.html#type-revisions-and-versions