Clarify JSON encoding

[itszootime]

Mostly for array (e.g. Double[].class) DataDescriptions, and ensure the most usable format.

[itszootime]

Also,

{ "type": "Request",
  "identifier": "ExampleProcess",
  "inputs": [
    { "identifier": "InputA",
      "data": "input data" },
    { "identifier": "InputB",
      "data": "some more data" }
  ] }

Or (as it is currently):

{ "ExampleProcessRequest": {
    "InputA": "input data",
    "InputB": "some more data"
  } }

Or (hybrid):

{ "type": "Request",
  "identifier": "ExampleProcess",
  "InputA": "input data",
  "InputB": "some more data" }