Qt style note

暫存區，還會修改


QWidget.setStyle() 不會拿ownership，要用setParent()才會一起清掉


我修正OBS一個memory leak ?

QString styleName = slider->style()->objectName();
QStyle *style;
style = QStyleFactory::create(styleName);
if (!style) {
    style = new SliderAbsoluteSetStyle();
}
else {
    style = new SliderAbsoluteSetStyle(style);
}

style->setParent(slider);
slider->setStyle(style);