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>