Model navigator shows change flag, if only library models are dirty; user cannot easily find the dirty model.
The dirty flag of the model navigator considers both models and libraries. However, the navigator displays only models or libraries.
Should there be a second navigator instead of the state-switch button for library and non-library view?
(from redmine: issue id 1157, created on 2013-01-14, closed on 2018-02-14)