* Fixed zookeeper not restoring layout properly if ZK is closed when scene is saved, max is restarted and scene reopened
* Fixed error message when dragging output of some schematic objects (in rare cases)
* Fixed error messages caused when rendering automatic previews (the code was not thread-safe, it now should be)
* Node previews are now not rendered if schematic view is not currently in focus (ie. if ZK is closed)

* Parameters that have local name "??" but a good internal name are no longer ignored