Current 4.0 release does not work with Qt > 5.9 and starts with black screen

The current 4.0 release still has a long-fixed bug in the cmake scripts that breaks it for Qt > 5.9 (broken regex that assumes 1 character for the minor release number).

The other big issue is #164 (closed) that causes users to be greeted with a black screen unless they figure out to change the renderer.

Maybe we could have a new release soon?