Add acceptance test for blocked YouTueb API with HTML5 sources

raise ItemNotFoundError if course not found in modulestore (course_listing) 

When the video has both YouTube IDs and HTML5 sources, and
the YouTube API is blocked, then HTML5 sources should be
used.

Fixed legacy dash numeric placeholders with named.

STUD-1455

Internationalized open ended panel headings.

LMS-2169

Conflicts:
	lms/djangoapps/courseware/features/video.feature

Valera/fix multiple videos on page release

Part of BLD-972.

If there are several videos on page, make sure that
the global onYouTubeIframeAPIReady function is properly
setup so that all callbacks are trigerred when the YouTube API
loads.

BLD-972

Add metrics to comment_client requests

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

This captures real-time metrics for all of the comment client actions,
segregated by course_id, as well as other small-cardinality fields.

The goal is to be able to detect changes in forum usage, with the goal
of alerting on potential error conditions.

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

Unicode support fixes