QtIFW

use right types to interact with WinAPI

 - the problem is that a bool variable is not big enough to get the result
   of CheckTokenMembership this causes in random memory corruptions

Change-Id: I16d07ae9af1e5991990ed010a8c4fdb463e5e833
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>