Do some helpful things in base job.

The jobs will need to know about the assignment they're running the job
for.  With that reference they can read the configured attributes for
  that perspective and for the source.
Jobs can write data associated with the assignment.

Bunch of changes that don't actually do much yet.  The job has access to
a data method that will be written to redis, associated with that
particular PerspectiveAssignment.  In a little bit I will serialize that
data and send it along in the serializer so that it can be displayed.

Also refactored (sort of) the PerspectiveAssignment class.  It still has
all the same responsibilities, but the different aspects are moved into
concerns.
Show real data in the templates.

Ouch.  First, what is called "data" in the controllers was switched to
"payload" midstream because it seems like it's a reserved ember term.
So that was fun to sort out.

The databinding stuff wasn't that bad.  The payloads are real model
objects in Ember so that they can be easily updated with new data later
and have the view reflect the changes.

I figured out that I can sideload the payload in the create action to
stop if from making a request, which I should probably tweak the
configurable attributes to do as well.  I still might need the API
endpoint for deep linking on that one, though.