- Use QPainter current pen for selected text in cases we
didn't specify it explicitly in the TextPalette.
- Better rounding of QRectF from QFixed values to QRect selected
background filling areas.
- Using QPainter::viewport() instead of random huge QRect() in
clipping, because it fails to apply this huge QRect() clip region
in Retina paint devices: 2x scale QMatrix::map() is not defined for
QRegion-s having rects with sum of dimensions larger than 100000.
