WIP: Combined Login/Registration: Set up basic enrollment infrastructure.

I wonder if these comments could be a little more descriptive and/or better placed. If this is meant to be a multiline comment, you might want to use the block comment format @AlasdairSwan has been using, for consistency ([example](https://github.com/edx/edx-platform/blob/diana/enrollment-integration/lms/static/js/student_account/views/LoginView.js#L58)).