Hi,

the following patchset upgrade xpra to version 4.0.2, which will finally
use Python 3 and GTK 3. It removes the Python 2 variants of PyOpenGL,
because xpra is the only dependent. I’ve been running this package for a
week now and connected to both version 4 and version 3 on an Ubuntu
machine, which still works. OpenGL also works, despite failing tests for
PyOpenGL.

Rutger: You have been working on xpra in the past. Could you take a
look and make sure I did not break any use case?

Cheers,
Lars