disable getFileTimeFromProperty on Unix systems

 - it is not working correctly at the moment and will be fixed later

Change-Id: I0527410f09fbdff33e6851558482bf329ba80de6
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>
fix crash in scriptengine autotest

 - destructor deletes components, so there was a double deletion

Change-Id: I5c4f14bb3b964297be542821d10a7ebb27925af5
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>