JDK duplicates classes due to org.osgi.foundation

I've noticed in the IDE (Eclipse, but would be same in Intelli) when doing a Ctrl-Shift-T to look up e.g. java.lang.String that, somehow, we have it twice on the classpath - once from the installed JDK, and once from a regular JAR - the org.osgi.foundation.

This has at least two issues:

1. minor annoyance when looking up classes in the IDE during development

2. during code, and running unit and component tests in the IDE, depending on the (normally unpredictable) order of classpath entries the wrong JDK classes could be picked. (During runtime in Karaf this org.osgi.foundation is, hopefully, not present.)

See also e.g. https://bugs.eclipse.org/bugs/show_bug.cgi?id=343069.

Let's try to exclude org.osgi.foundation ...