I used xserver-xorg-input-libinput from yakkety yak proposed, so now I'm indeed on...
It's fully working now! Running /usr/lib/gnome-settings-daemon/gsd-test-wacom somehow...
I can't configure it graphically (doesn't respond to the buttons and settings have...
Output: xserver-xorg-input-libi 0.18.0-1 amd64 X.Org X server -- libinput input driver...
Cintiq 24HD: pad not showing up in /dev/input, xinput, xsetwacom