Require instance_attributes and cluster_property_set to have an ID and

optionally a score attribute which we use to determin the order in
which they are applied.

CVS patchset: 9112
CVS date: 2006/04/06 10:48:18

Mercurial revision: ecc70a7042d0a9261e8426922a3a5bb0c45b97d2