avoid errors when forward-migrating course_groups after south conversion

JIRA: TNL-937

TNL-670

JIRA: TNL-710

IMPORTANT: this commit converts the course_groups
package to using migrations.  When deploying to an
existing openedx instance, migration 0001 may fail
with an error indicating that the CourseUserGroup
table already exists.  If this happens, running
the 0001 migration first, with the --fake option,
is recommended.  After performing this step,
remaining migrations should work as expected.

TNL-649

Remove antiquated cleanup script

Remove extra prerequisites style and class

Add compare-branch option to paver run_quality

Fixed plus sign icon for overall grade range add button.

TNL-890

Refrain from setting email opt-in preference when checkbox is missing

FIX - LMS: Calculator Toggle Label Display

Add BI events for tracking email opt-ins

Conflicts:
	lms/djangoapps/mobile_api/course_info/tests.py

Make static URLs absolute in handouts, updates, and about for mobile API

Allowing email optin to work on register.

Cdodge/shopping cart touchups

Sylvia/docs/1162

Login/Registration A/B test cleanup

Fix issue with iframe redirect

Only allow users who turned 13 before this year began to opt in.

Add support for redirect URLs in third party auth for combined login/registration page

Remove old login/registration acceptance tests

Add deprecation warnings to old login and register views

Move third party auth util to student_account

Add exception for microsites

Fixed instructor dashboard tooltip far away issue.

TNL-558

Fix paver test_js task to work without -p flag

JIRA: MA-147

This reverts commit fb6579abfdb6fc9fb8bc9233554ff5c6e9215659.

JIRA: MA-147