Merge rc to master

This reverts commit a16f5487.

Deleting a child of a unit should convert the unit to draft

Sarina/070714 language update

Conflicts:
	lms/djangoapps/instructor/views/instructor_dashboard.py

BLD-1117, BLD-1217: Add read-only list of Group Configurations, Create feature flag.

if the unit is draftable but isn't yet draft.

Add openedx-analytics discussion group to CONTRIBUTING file

Fixes has_changes to search all the way to leaf nodes

skipping update assets, not just collectstatic, in unit tests

Use deprecated course_key when calling the analytics API.

Previously it was serializing the course_key directly, which is not
interpreted correctly by the API.

Don't show 500 errors if connection to data API fails

Some of the metrics on the instructor dashboard are computed by the new
analytics data pipeline. Don't show 500 errors if the connection to the
pipeline API fails. Instead display that the data is not available and
log an error.

AN-1476

Missing "_()" in course_module.py

BLD-1217: Create feature flag for switching Group Configurations editing on and off

Revert ORA2 release

Make the strings in "Advanced Settings" page localizable

The fields should be translated before render into html templates.

Adds subtree_edited_on, subtree_edited_by, and fixes has_changes

Forum sidebar improvements

The home button is removed, the search box is always displayed, and many
visual adjustments are made, along with a large amount of refactoring.

Originally reviewed in #4211

Thread entries now show an activity count that includes the original
post, and only one of the vote count and activity count is displayed
based on the user's selected sort. The sorting and filtering options now
both use a select and are somewhat more verbose, and the visual styling
of the sort/filter bar is updated.

Originally reviewed in #4165 with a bugfix in #4211

The rendering of the link happens in an event handler, and the
collection's attributes were not getting set properly before the reset
event triggering the rendering occurred.

Originally reviewed in #4072

A thread will be labeled if it is pinned, if the user is following it,
or if it was authored by a staff member or community TA. This also
slightly changes the color used for community TA labels.

Originally reviewed in #4072

Use larger and lighter title font, decrease padding, and use lighter
solid backgrounds instead of gradients. Also, refactor SASS code to
conform better to our new style, including using more specific class
names.

Originally reviewed in #4072