WIP: Merge branch kotlin partly
Moved tests to https://gitlab.open-xchange.com/engineering/gradle/osgi where the code lives now. Tests are running now here: https://jenkins.open-xchange.com/job/engineering/job/gradle/job/osgi/job/master/lastCompletedBuild/testReport/com.openexchange.osgi.data/OSGIManifestTest/