Runtime only resources

Fixes various issues related to Resources that are not persistent, primarily ensuring that Resource.isRuntime() and ManagementResourceRegistration.isRuntimeOnly() provide the correct value.

This is needed for Alexey's work with non-xml-based persistence of the management model. The various hand written xml persisters have hard coded logic for dealing with this kind of thing, but we need to be able to use the Resource and MRR APIs to determine why resources should be persistent.