Changed setting of output to work like setting of selection in live
panel: the output of the model is changed, then a correspondig change is
sent out, and, only when recognizing such a change, the view is updated
accordingly (as opposed to setting output directly some times and then
directly other times implicating kind of a mess in coordination).

Signed-off-by: Jakob Brandsborg Ehmsen <jakobehmsen.github@gmail.com>