anchor.diff:                      "primary_language": "es_MX",
                       "workflow_version": "22.1",
                       "content_language": "en_US",
  +                    "first_task": "interest",
                       "tasks": {
                            "interest": {
                                "type": "drawing",
  
positive.code:                     "primary_language": "es_MX",
                      "workflow_version": "22.1",
                      "content_language": "en_US",
                      "tasks": {
                           "interest": {
                               "type": "drawing",
  
negative.code: *id*, *created_at*, *updated_at*, *workflow_version*, *content_language*,
  and *classifications_count* are assigned by the API
  
  A workflow's `tasks` is a hash of keys to task definitions.
  
  A workflow's `first_task` is a string matching the key of its first task. (The order of keys in JSON hashes is not guaranteed).
  
  Each task has a `type` string of "single" or "multiple" choice, or "drawing". (More task types to come, e.g. Serengeti-style filter and Sunspotter's comparison.)
  
  Each task has a `next` string, linking to the next task in the workflow. If this is `null` or not defined, the workflow ends.
  
  Each task may have an optional number `required`, which when set will force the user to provide a certain number of values before moving on to the next task. (This had been a boolean; `true` will be cast to `1`, `false` to `0`).
  
  Each task has a `question` string telling the user how to complete the task.
  
  "single"- and "multiple"-type tasks have an `answers` array.
  
  Each answer has a `value` (of any type) recorded in the classification and a `label` string displayed to the user.
  
  Each answer in a "single"-type task may have an optional `next` string overriding the task's when the answer is chosen. Explicitly setting this to `null` ends the workflow.
  
  "drawing"-type tasks have a `tools` array.
  
  Each tool has a `value` and a `label`, just like an answer.
  
  Each tool has a string `type`. Options include:
  
  + point
  + ellipse
  + circle
  + linke
  + axes
  + rectangle
  + polygon
  
  Each tool has a string `color`, which is applied to the marks made by the tool. Any format valid as CSS can be used.
  
  + Model
  
      + Body
  