While the user is touching the screen, postpone scrolling
until we get a touch release. Scrolling in the middle of
a touch sequence will change the coordinates under the
touch, and cause some artefacts.
Change-Id: I02ef420abaab780a459f014d4b4cfb75c8fbb725
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>