Microsites alongside Theme

Contentstore streaming range

Mark calls to track() on pageload as noninteraction events

Currently, users can only download ContentStore files from first byte to
last byte.

With this change, when a request to the ContentStore includes the HTTP
"Range" parameter, it is parsed and StaticContentStream will stream the
requested bytes.

This change makes possible to stream video files (.mp4 especially) from
the ContentStore. Users can now seek a specific time in the video
without loading all the file.

This is useful for courses with a limited number of students that
doesn't require a dedicated video server.

Update comments to point to openedx.atlassian.net

Fix Video Player Pause Issue

Rewrite course url matcher to not be greedy

Make it branch agnostic

LMS-11210

Conflicts:
	common/lib/xmodule/xmodule/modulestore/split_mongo/split_draft.py

LMS-11181

Added a relaunch invitation template email

And whitespace corrections (automatically made by my editor, and I'm too lazy
to remove them)

Translation & secure-aware changes to studio's settings page

1. Change the link of course's about page secure aware, which displays 'https' or 'http' prefix according to the current protocol.
2. Make the email in this page translatable.

Add ability to set staff lock from course outline

Dhm/import split test

Instructor Dash: Display message when no tasks running 

This commit adds a message to the instructor dashboard that is displayed when
no instructor tasks are currently running. This message is displayed where the
instructor pending tasks table would normally be placed, and is replaced
with the table when there are running tasks.

Anton/sync groups and verticals

set root logging level for acceptance tests to ERROR

Add a request-token to identify which xblock html was rendered as part o...

Auto enroll students even if there are multiple course modes

[STUD-2903]

Update i18n-tools

make unit tests respect mongo port/host settings (with default)

Add session middleware to an external auth test to fix a test failure with the auto-registration AB-test changes

Use English for the marketing site buttons in an edx-controlled domain

Update the reference to gsehub/xblock-mentoring#4

Email content history fix and additions

This addresses a bug in the email content history table where
"Unknown" was displayed in the number of emails sent column if any sort of
failure occurred during email sending. This behavior has been editted so now
the number of emails that failed to send is displayed, along with the number
of emails that were successfully sent. If the email task is still pending,
"0 sent" is displayed.

As a small addition, the table now also includes the authors of previously
sent emails, and the modal window for an email also displays its author.

Minor i18n fixes prompted by translators