rdflib, JSON graphs, Object Serialization

Changed to installed rdflib and added rdf-json and json-ld formats as well as trix, trig, turtle, and other representations.

Added recursive serialization, replacing the /l endpoint with a function that returns the entire object tree below the current resource as a single JSON, including the graphs. 

The intention is to be able to make objects or sub-objects by cloning from other objects or templates.