Replaced fixed models with a dictionary #33
Description
Currently there are two RDF models in a "Twine graph" - the "old" model (populated by sparql-get, containing the previous state of the graph being updated), and its replacement, which most processors deal with.
By replacing these with a dictionary - i.e., a set of (name, model) pairs, we can improve workflow flexibility.
The sparql-get processor would then be transitioned to populate a specific named model (defaulting to "old").
Other processors could become configurable along similar lines, allowing for—for example—particular models to be uploaded to specific storage buckets (something spindle-generate currently has to do itself)