Support for resources that are backed by data bags

This will be used by things like the load balancer/image specs, AWS resources, anything else that needs to persist a little bit of state data in a data bag. 
It feels like the action should be passed in by the provider for all these ... I think it's supposed to report the actual action on the provider, and if it isn't the same as we assume here, we should report the real one the user typed.