Runnable should have name of stamped object in its status

[squeedee]

Runnable should reference the stamped object currently reflected in the status.

In worklaods and deliverables each resource that was stamped is referenced in a `stampedRef' field

We should do the same for Runnable, naming the current (most recently stamepd object) in status.stampedRef

[squeedee]

Waiting for the user requirements to decide wether this is a valid design.