This allows a keyboard shortcut to move a client to a different amiwm
screen. That way when you have things like Firefox restart every window
in a single screen, you can quickly move screens to where they should be.
Although it likely doesn't matter /that/ much, the x11 xlib manual
does say to use it rather than expecting the struct to stay the same
size.
Yeah yeah it's 2022 and we really do build things from source,
ICCCM is likely not going to change that much nowdays, etc, etc.
