Refactor CCX schedule.js

[pdpinch]

From a conversation with David Baumgold in the ccx channel in Slack:

I don’t think you’re using Backbone’s View system properly, to ​_render_​ the client-side templates.

The whole point of a templating system is to avoid having to do complicated mutation of the DOM structure after the fact.
doing that complicated mutation quickly becomes difficult to read, and makes it harder to maintain the code