Make Rectangle border be inner instead of centered on the outline.

Make Rectangle border be inner instead of centered on the outline.

This avoids awkward situations such as when clipping to a parent item of
the same size and makes it easier to reason about the bounding rectangle
of the item.

Task-number: QTBUG-21341
Change-Id: If015cfbc5792429f4a407fc0547ea71eca779eda
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Reviewed-by: Laszlo Papp <lpapp@kde.org>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>