Add surface format to QQuickWidget.

Change-Id: Id72a042588e37832a0d3757bad935c531ef8275a
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Dynamic GL in Quick

The counterpart to I716fdebb. Implements the dynamic path
in scenegraph.

Task-number: QTBUG-36483
Change-Id: I2dc613ba84560b7b8e36d3cd1da61c050ab08db0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>