* Also adds "Delete" as part of the context menu of devices.
* (Some methods are reordered for consistency; Legacy signaling is fixed to the new one where encountered)
* Patched build_pyqt.py for Windows, and for it to remove the path of the .ui file in the comment.
* Shrinked the minimum width of all preference dialogs.
* Removed zorder nodes (PyQt5 complains...) and regenerated all preference dialogs.
I drop some related cloud support, we will restore it when we will be ready.
* Switch to Python3 super style
* Drop old object inheritance
* Fixed old super call