Confirm packager build is working across all distributions

Present new 16.4 features and changes to OP Team

Create 16.4 release teaser

Create and publish 16.4 release video

Identify new Enterprise add-ons for the 16.4 release (if relevant)

Update 16.4 Glossary with new terms

Update OpenProject image in openDesk

Release 16.4 PR communication: heise and more

Release 16.4 image for blog post and newsletter, incl. feature image

Ensure that packages are installable