qdoc: broken \qmlproperty enumeration

There is no way to define proper enum properties in QML, so we have to use int. Such properties are still documented as enum, though, and qdoc used to respect that. Since Qt 5.2.x the type appears as int in the docs.

Examples:

• \qmlproperty enumeration Slider::orientation
  http://doc-snapshot.qt-project.org/qt5-stable/qml-qtquick-controls-slider.html#orientation-prop

• \qmlproperty enumeration SpinBox::horizontalAlignment
  http://doc-snapshot.qt-project.org/qt5-stable/qml-qtquick-controls-spinbox.html#horizontalAlignment-prop

• \qmlproperty enumeration TabView::tabPosition
  http://doc-snapshot.qt-project.org/qt5-stable/qml-qtquick-controls-tabview.html#tabPosition-prop

• \qmlproperty enumeration TableView::sortIndicatorOrder
  http://doc-snapshot.qt-project.org/qt5-stable/qml-qtquick-controls-tableview.html#sortIndicatorOrder-prop

• \qmlproperty enumeration TableViewColumn::elideMode
  http://doc-snapshot.qt-project.org/qt5-stable/qml-qtquick-controls-tableviewcolumn.html#elideMode-prop

• ...

PS. It still worked in Qt 5.1, see for example Slider::orientation: http://qt-project.org/doc/qt-5.1/qtquickcontrols/qml-qtquick-controls1-slider.html#orientation-prop.