All the dialogs in the wiki are now accessible to screen readers.

Also, the "Switch to selected version" button did the odd thing of
reloading the page with the new version selected, but inside a dialog.
That is now fixed.

The merge dialog has a warning that looks kind of funky still, but you
can read it, unlike the previous code.

LMS-1337

Also cleans up test_view_authentication to use user factories for
various user classes

remove field_data_cache from grades.grade and grades.progress_summary

cleans grading code by adding wrappers

Having ENABLE_S3_GRADE_DOWNLOADS enabled by default in common.py
could lead to surprising behavior for folks downstream. They'd
suddenly see a grade download screen on their new instructor
dashboard, but the links by default would be local files and
couldn't be used in an actual production environment. So we disable
by default and let people explicitly enable it and set it up for
S3 if they wish.

LMS-58

that are not present in a given student's gradeset.

General code cleanup and addition of comments.

Instructor dashboard API unit tests.

LMS-58

Restrict grade report generation to 'is_superuser' users (can be overridden with
feature flag ALLOW_COURSE_STAFF_GRADE_DOWNLOADS); all staff users can download
generated files.

LMS-58

Hook up display of grade files ready for download to new instructor dashboard.

LMS-58

The tab names are not being translated

remove field_data_cache from grades.grade and grades.progress_summary

cleans grading code by adding wrappers

Also, display a message on their dashboard.

The input string is not expected to contain any unicode characters

LMS-1475

AJAX requests on forums pages occasionally fail (usually when a request
to the comments service times out), but the user is not made aware of
the failure. This manifests as either the system not appearing to store
state (e.g. if an attempt to flag a post fails) or something taking
forever to load. Now, a modal will pop up to alert the user that a
request has failed and instruct them to reload the page.

In the longer term, we should fix each user gesture that results in an
AJAX call to gracefully handle a failure by resetting the state of the
world appropriately and aleritng the user.

JIRA: FOR-37

Stop video skipping links from showing up when not needed and address the issue of skip links for multiple videos.

Fixes BLD-521

into beta dashboard.

Also includes new functionality, in both legacy and beta
dashboard, to include appropriate email text for a
Shibboleth course.

This reverts commit 19dd49f3.

LMS-1487