Fix winrtrunner device detection and deployment for WP8.1

Add device detection for WP8.1, and use the Appx packaging codepath
for these devices. Rely on winrtrunner to automatically select the
correct profile.

Change-Id: Ibd1d415644fdc8fd007969be25213410c3c0e0a7
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>