Clean up xmodule tests
Make Location into a UsageKey
Cleanup of get_lms_link_for_about_page
Make CourseLocator a CourseKey
Respond to review comments
Start to remove Location.course_id
Update loc_mapper.translate_location to only take a location
Fix up ORG_SEPARATOR in CourseLocator
Remove more references to Location.course_id
Considate on a single IdReader class
Fix more xmodule tests
Changed signature of get_items and impl'd in old mongo
Use + to separate org from offering
Fix missing id_reader
Add CANONICAL_NAMESPACE to old-style keys
Call Location with explicit values, rather than using the overloaded form
Fix get_base_url_path_for_course_assets
Make course_module do the right thing to get a course_key
Establish pattern for make_usage_key_from_deprecated_string
Change grades.py to use that and use get_item instead of inefficient get_items
wip for test_contentstore fixes