Editor: make it possible to edit instances that are covered by another
Given that we move through a cell - If an instance is located behind another one it would be nice to have it's shape (borders in red or white, pulsating) shown "within/on top of the covering instance". Toggling this on and off by a keyboard-shortcut like ctrl-shift-s(ow covered) would be best. A covered instance should be selectable somehow, e.g. by clicking on it's shape. I know that the shine-trough will become a problem quickly if there are a lot of instances positioned after each other. Maybe there is a way to handle this somehow, like offering a dropdown list of instances that are placed behind a selected instance - ctrl-l(ist) or by just showing the closest covered instance.
(RM-2600 from redmine: created on 2015-06-01 by Who Knows, , closed on 2015-06-02 by nobody)