Detchar recommendation versioning
It would be desirable to be able to have multiple versions of detchar information.
At present only one set of detchar recommendations can be stored on a "per-event" basis, although it is possible to specify these recommendations on a per production basis as well. It is likely that over time these recommendations may be updated, and productions which use the old recommendations should be deprecated.
We therefore need a way of ensuring that the old versions of the recommendations are mapped back to deprecated productions, but also that we automatically deprecate (and potentially respawn with updated configuration) productions which used them.