to get duration spinbutton working need to know where the cursor
is in the spinbutton and to change the adjustment factor depending
on that, and need to additionally disable the vcl round to nearest base unit on
up/down

Change-Id: I6dd09e1639454cb4820d3aeb0c0c698fcebd417e
Reviewed-on: https://gerrit.libreoffice.org/54065Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>