Fix sorting order of main components in install tree

Put the latest Qt version on top and Tools component at the bottom.
Leave some "space" between sorting priority numbers.

Change-Id: Ib470fa5bf31e1bec1e970026a13c5697bd05132b
Reviewed-by: Jani Heikkinen <jani.heikkinen@digia.com>
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>