Add Windows Phone 8.1 supported sensors

AmbientLight as well as Orientation sensors have been added to the
Windows Phone 8.1 API. Furthermore accuracy for QCompass is now
available on all WinRT related platforms.

[ChangeLog][Windows Phone] Add support for
QAmbientLightSensor and QOrientationSensor with Windows Phone 8.1

Task-number: QTBUG-39627
Change-Id: I6b2674c0d9935b874f35e6453f1e51d811133264
Reviewed-by: Andrew Knight <andrew.knight@digia.com>