Fix test_course_id_clash.py by making it possible to construct course modules with a carefully constructed ItemFactory
Make Studio able to handle deprecated key formats in urls
Replace uses of slashes: and location: style urls in tests
Use the new locator interfaces
Remove tests that rely on creating multiple courses that differ only by case
Remove uses of loc_mapper
Correctly map data pulled from the db using values to the right python type
Make courses not marked as detached, but still allow construction of them via factories
Be specific when checking for empty course_key
Maintain compatibility for default wiki slug