Rename define-model-query and tidy up

Write some examples
A dynamic JSON-QUERY (WIP)

Largely related to CONTAINS operator.

After much stuffing around it seems that this is about as useful as you
are going to get before it just being cleaner to break down and write a
full define-model-query type query, since they are relatively easy to
do.  Certainly once you get into :where clause you might as well have
the 'prepare' and then call cycle...