Add tests for has_course

Dhm/opaque dont skip

Fix paver python prereq paths

Fixed change log table format & pdf errors

i18n: Make values that has 'display_name' be displayed localized in editor

Opaque keys

Dhm/no package

and negative tests for get_course.

STUD-1592, STUD-1603, LMS-2642

Updates to problem location for opaque keys

Cheatsheet visibility code refactored.

Updated changelog

Fix gen_cert_report to use CourseKeys.

copied from LMS aws_migrate settings

Clytwynec/rake2paver quality take2

Redirect most studio access through draft modulestore

Make SPOC gradebook an API feature

Add some missing AUTHORS

rather than have caller figure out whether to call draft or direct.
Fixes get_children to always find draft children in studio.
STUD-1662

rather than just hacked in to the instructor_dashboard base file.
Also move the tests from the legacy implementation to the new dash API implementation.

Remove Video player outline.

Remove some outdated code.

i18n: Make XBlock buttons & components have localizable display names

i18n: Fix an i18n string extraction problem in 02_html5_video.js

Bok-Choy Video Time Tests

Fix youtube regular expression in video player editor

Replace a string concation to a single string to prevent the partial extraction of the string.

1. Current code uses type name as the display names for XBlock buttons, so the name of these five buttons can't be localized. This fix contains code that adds a 'display_name' field for the buttons, and makes their names localizable.
2. The display names of components in advanced, html and problem types can be localized now.