Each part of a split table needs to supply rows for the same objects.
We currently require each part to name its objects explicitly, with an
object ID field, and don't support splitting tables that don't have
such IDs. These restrictions became arbitrary when commit 4e23c45
implemented checking each partial table supplies the same rows. Relax
them.
Affects tables sect, news, lost, realm, game, infrastructure.
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
