Object model that represents the standalone configuration schema.

Note that it's quite possible that there will not be a separate, distinct object model for this and the object model that represents a regular Server in a Domain will suffice. Or perhaps we'll provide a class that provides a view onto the regular Domain/ServerGroup/Server object model for use by clients (e.g. embedded AS users) who want a simplified view.

Key thing is we don't want every subsystem that needs to understand the domain configuration model to have to understand both the standalone and the full variant of it.