Add count to interface
Only make queries (and their make fn) in one place
defun-make-query becomes just make-query
Add db-name-string
Trivial doco fixes
Add some symbol/json/mop utility functions

We need these for the new CLOS version of model parameters
Clean up logging of interface and transactions
Re-purpose model parameters specials to just decls
New CLOS model parameters

This commit will not build, still to change interface
Model parameters JSON de/serialization clean up
Add closer-mop dependency
Change create-model to use new model parameters
Change backend to use new model parameters
Change queries to use new model parameters
Tidy up informal tests, no longer in own schema

Export some extra symbols to support tests.
Add some TODOs
Informal tests build now, update comments

New model-parameters code now all in place.