- Wsmouse_input() get new argument 'flag', which indicates whether x/y/z are
relative or absolute.
- Wsmouse get new io controls, WSMOUSEIO_SCALIBCOORDS and
WSMOUSEIO_GCALIBCOORDS.
(done by directly setting zilog chip control bits -- there should be
a zs_set_frame() or so in z8530sc.c)
fixes PR port-alpha/8423 by Konrad Schroder <perseant@hhhh.org>