edit: Report ship and land unit commodity change properly

edit: Report ship and land unit commodity change properly

Print a message describing the actual change.  Necessary to give the
deity a chance to catch unexpected changes, e.g. a player unloading
stuff right before the deity edits it, leaving fewer items than the
deity intends to take.  Watching out for such changes is especially
important with non-interactive edit.

Send bulletin to owner and report news exactly like the give command.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>