An element cannot be added to the same parent without removing it first.
Using ECollections.move to move the element in the same container.

Change-Id: Iddf6333450b02a6630803196b2ffa3025f0a578e
Also-by: Lars Vogel <Lars.Vogel@vogella.com>
Signed-off-by: Rolf Theunissen <rolf.theunissen@gmail.com>