WinRT: Support screen orientation changes

The title says it all.

Change-Id: I9b0d8bc2513a4542b030ac82da2f0b5a41041712
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Fixed unused variables warning in QEventDispatcherWinRT

Change-Id: I93684fe861608c1080a416d97e7f9427bd3cb299
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@digia.com>
Fix winphone makefile generator

The shader compiler should be kept in the path in order to
build ANGLE.

Change-Id: Ibf93a5e7fcb98c2710f1da67f094a439b3f2913d
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
WinRT: Refactor pointer handling

This commit aims to improve efficiency and correctness of pointer event
handling. Touch events are now tracked. Tablet events are now
supported. Runtime resources are now properly released.

Change-Id: I8616b631f8aef81f82181ff014e9df9b24727232
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>