BLD-1190: Fix bok-choy test.
Merge pull request #4441 from edx/anton/fix-flaky--bok-choy-test

Video: fix flaky bok-choy test.
Make TinyMCE editor translatable

Combine TinyMCE's built-in translation scheme with the django's translation framework.
So edX's translators can also make translations for TinyMCE used in edX.
Merge pull request #4349 from louyihua/localization-cms

Make TinyMCE editor translatable
Add tests of cross-modulestore import/export

[LMS-2945]
Skip DraftVersioningModuleStore tests
Add the manual testing course for testing xml import/export across modulestores
Explicitly create the AssetKey for all assets coming out of a ContentStore
Don't use raw asserts in split (to handle different types of UsageKeys sanely)
Only compute block types with children once
Use field scopes to compute which metadata to strip from the definition during XML import of XMLModule subclasses
fix shib reg from course about page
Merge pull request #4445 from cpennington/cross-store-xml-import-export

Add tests for xml import/export between different modulestores
removing thread-local cache for branch_setting
recommender prototype
Merge pull request #4303 from edx/danielli/recommender_prototype

recommender prototype
Merge pull request #4464 from edx/jbau/remove-branch-setting-cache

removing thread-local cache for branch_setting
Merge pull request #4450 from Stanford-Online/jbau/edx/fix-shib-student-register

fix shib reg from course about page
Instructors can view previously sent email content

Previously on the send email page of the instructor dashboard, instructors could only view task information about emails they've sent for their course in the past.
In addition to this, I've now added the ability to see the content of all previously sent emails. A "show email content history" button has been added to the page. When clicked, a table displaying the subject line, number of emails sent, and date/time of submission for each previously sent email is created. An instructor can then click on any subject line to see the content of that email, displayed in a modal window that appears on the page. The window is also equipped with a "copy email body to editor" button, which copies the emails contents to the tinyMCE editor, so that an instructor can easily resend an email that they've sent in the past.

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