JSON template for a 'complete' metadata record

Incorporates concepts from ISO 19115, 19115-1, 19119, FGDC, 19110, and FRBR along with some additional stuff like recording the lineage of the metadata record, which is useful in a metadata harvesting federated system. Builds on the conceputal model presented in a previous discussion here.

This is an experiment to see what it would look like, trying to bring in just about any metadata property from those various specs... Lot's of comments in line.

The JSON is not perfect -- I'm a newbie.