It seems the largest possible value is to be passed, so actually pass
that instead. Note that even though the name of the xcb_get_property
parameter is called 'long_length' its actually a uint32_t.
https://bugzilla.gnome.org/show_bug.cgi?id=751136
It's been long enough. We can mandate support for these, at least
at build-time. The code doesn't actually compile without either
of these, so just consider that unsupported.
This is specifically about managing X11 windows, not necessarily
running as an X11 compositor. By that I mean that this code is
still used for XWayland windows, and event handling is still and
modesetting / monitor management is still in core/.
This is also a fairly conservative move. We don't move anything
like screen.c or bell.c in here, even though those are really
only for X11 clients.
