Cancel in-flight AJAX requests that aren't needed.

[trmcnvn]

ember-concurrency doesn't cancel any requests that are within a canceled task, and ember-data doesn't have a supported way of canceling a request.

We should investigate canceling these requests for the consumer as it's data that isn't relevant anymore.

Can be achieved by a method similar to: https://gist.github.com/vevix/00e7d68c7d16a7ec5cafc64ea92c6176

where yield'ed tasks would be wrapped in a try / finally block:

try {
  return yield get(this, 'store').query('model', { ... });
} finally {
  get(this, 'store').adapterFor('model').cancelRequests();
}