Qt widget: migrate QGLWidget object to QOpenGLWidget introduced in Qt 5.4
Qt 5.4 introduces a new object called QOpenGLWidget to replace QGLWidget used in Monteverdi.
The difference is described in qt documentation:
It brings new features, fix some issues with double screen (see https://stackoverflow.com/questions/33545006/qt5-attempt-to-set-a-screen-on-a-child-window-many-runtime-warning-messages#34066254)
I think that QGLWidget is now deprecated in Qt.