Android 5.0: add missing state transitions

Android 5.0 introduced control state change transitions. Without this
change, CheckBoxes and RadioButtons don't transition between checked
and unchecked states as appropriate.

Task-number: QTBUG-42520
Change-Id: If2aa70898e72b78f105732cc4ee5c9674cc6082c
Reviewed-by: BogDan Vatra <bogdan@kde.org>
Reviewed-by: Caroline Chao <caroline.chao@theqtcompany.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Only make scrollbars non-interactive on mobile devices.

Before this patch, I could not adjust the scrollbars in a ScrollArea on
a Windows 8.1 desktop computer just because it had a touch screen.

The same problem was observed on Linux (with touch screen).

Task-number: QTBUG-42806
Change-Id: I6f35c40b0362820d7c1685e1b6fc8474432237eb
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Take all offsets into account also with PlatformMenu

Task-number: QTBUG-42314
Change-Id: I7e63d744bbed4a5c254d6cffdc8aba4c5e37d5c3
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@theqtcompany.com>