In some cases it would be useful to initialize QPainterPathStroker from QPen

In some cases it would be useful to initialize QPainterPathStroker from QPen. A typical pattern is to create a QPainterPathStroker which matches a
QPen by calling methods such as setWidth etc. This could be done if there was a constructor which takes a QPen and automatically sets up the QPainterPathStroker to match the settings of the QPen.