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

Sarina/070714 language update

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

Missing "_()" in course_module.py

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

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

Originally reviewed in #4072

Misuse of 'gettext' in mako templates

Make Studio able to handle deprecated key formats in urls

stupid simple css typo fix

Explicitly skip tests in common unless we know we're running the LMS unittest suite

add lms_base and cms_base urls to bokchoy envs

Updated Course End Date info

To translate strings in mako templates, the pattern of ```${_()}``` should be used instead of ```gettext``` even if the strings to be translated is located in a ```script``` block.