Adrien Di Mascio <Adrien.DiMascio@logilab.fr> [Tue, 17 Nov 2009 11:46:07 +0100] rev 3869
[server] remove not-so-useful entity_name and entity_attr functions, introduce entity_oldnewvalue
entity_oldnewvalue(entity, attr) is usable in before_update_entity and
returns both old and new value of entity