PyPi v1.5.0

• Using qtpy library instead of my own Qt5/6 mechanism

PyPi v1.4.0

• Adjusted the SS_GROUPBOX stylesheet: Groupbox title is now vertically
  aligned to be centered with the top line, regardless of the Qt lib. Nothing
  changes for PyQt5/PySide2, and fixes PyQt6/PySide6.
• Added function e8() to calculate the pixel width that is necessary to fit
  N number of '8's in the supplied font. In analogy to the 'em' font-metric,
  but now focused on displaying numeric values.

PyPi v1.3.0

• Neater support for PyQt5, PyQt6, PySide2 and PySide6

PyPi v1.2.0

• Added support for PyQt5, PyQt6, PySide2 and PySide6