Add datadog metrics logging for django model creates, updates, and deletes

Disable failing video test

Markhoeber/documentation/doc 105

DOC-105

Adam/merge release 2

Temporarily disable the bok-choy test that is intermittently failing

AN-167 New chapter on role & skills of data czar and research team

Skip video test that is failing in master

this will allow for clientside javascript reporting

Support emitting analytical events from xblocks running in the LMS

temporarily remove SR on capa alerts to fix problem submissions (LMS-247...

fix raw grade dump in standard instructor dashboard

Added test and cleaned up code formatting
Review based changes
Converting class method and attributes to private

Unicode support fixes

Reduce false cache misses when evaluating prerequisites

Nimisha/studio reorder and hide tabs

Settings for ENABLE_STUDENT_NOTES and ENABLE_TEXTBOOK in CMS.
Do not display empty collection tabs.
Updated Changelog.

* added in fixed state markup/logic
* added in collection markup/logic
* revised styling for page titles, collection, and fixed elements

Make YouTube mocked server serve YouTube API

1.) Making YouTube mock server serve YouTube API.
2.) Adding ability to block YouTube API from YouTube mock server.
3.) Adding acceptance tests that check YouTube mock server for availability of YouTube API, and for it's ability to block YouTube API.

Part of BLD-939.

Update doc string for YouTube stub server.

XBlocks can and should use the "publish" method provided by the runtime to emit analytical events. In theory we could now start replacing calls to track_function with calls to publish, however, that migration is not handled by this change.

Fixes: AN-789

LMS-1287: Added section for batch add of beta testers

Add an option to prevent multiple logins of the same user.

Included information on how to launch the server
on its own.
EOF

Fix failing tender.