I didn't think this would make up discussion like this. But the solution just to have two different library paths would do it.
Something for the future (and I mean future): Then pressing update in the IDE it automatic updates the program code of the IDE, core files etc. it then looks in some place there as many as possible libraries are located if any library that you have downloaded has a new version. If that's the case it downloads the new version of that library. As sad, for the future.\
JanD