ModeShape EAP subsystem ignores the "cluster-name" attribute, making the repository non-clusterable

In order to cluster ModeShape repositories in EAP, the cluster-name attribute needs to be specified in the repository configuration.

Even though the current kit fully defines the attribute (marshaling from/to XML, setting & reading it), it does not list it as a repository attribute. This means that in effect, when configuring a repository, the value will always be undefined.

In effect, this prevents ModeShape from being clustered in EAP.