Refactor the json-ld parser to not use a whole N3 library #349
Description
Currently the way JSON-LD parser has been ported into rdflib is a horrible kludge. It parses it, puts it into a store in a separate N3.js library which is imports, then re-serializes it into something which rdflib.js could parse anyway, and then parse that into the rdflib store.
This involves a huge amount of code and a huge amount of time.
Solution is to change the code of the jsonld parser to write directly to the rdflib store.
(This may be a dup of an earlier issue but I could not find that)