"submitter", thus making it possible for a single person to manage
multiple organisations, as well as for a single organisation to have
multiple different manages.
Re-hook events and news items to use organisation of the submitter
instead of the user who did the submission. (product listings already
did this)
part of the core, since it seems like it could be useful for other
kinds of objects as well in the future, but for now only the
software catalogue uses it.