QtIFW

Make cycles in component dependencies fatal

Warn the user when sorting operations fails due to cyclic
dependencies. Previously we would just continue, saving an
incomplete list of operations.

Change-Id: I0d80ad142e5d6936bbfab69835ff539a893cb180
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@digia.com>