Add support for rendering in a QtQuick scene

[Stéphane Magnenat]

As a first step, this can be done by embedding raw GL commands as examplified here:
http://doc.qt.io/qt-5/qtquick-scenegraph-openglunderqml-example.html

This should be available as an alternative viewer for Enki, in parallel to the one based on QGLWidget.