Implementation of JSON RFC 6902

[justinbhopper]

Implementation of a formatter that converts a json delta object into patch operations, according to JSON RFC 6902. https://tools.ietf.org/html/rfc6902

This is a port of the JSON formatter in the original jsondiffpatch. Like the original, it does not support TextDiffMode.Efficient, due to the fact that we are converting the delta into the JSON RFC 6902 spec and thus cannot distinguish between a text-diff and full-text operation.

I have also added unit tests.

Example usage:

var left = JObject.Parse("{ \"name\": \"Justin\" }");
var right = JObject.Parse("{ \"name\" : \"John\", \"age\": 34 }");
var patch = new JsonDiffPatch().Diff(left, right);
var formatter = new JsonDeltaFormatter();
var operations = formatter.Format(patch);

/*
operations: [
  { "op": "replace", "path": "/name", "value": "John" },
  { "op": "add", "path": "/age", "value": 34 }
]
*/

cc: @wbish

[wbish]

Thanks for working on this @justinbhopper. I've released 2.2.0 so folks can start using this since its been requested for a while.