BLD-1117: Add read-only list of Group Configurations.
Missing "_()" in course_module.py
Make the strings in "Advanced Settings" page localizable

The fields should be translated before render into html templates.
Merge pull request #4286 from louyihua/studio-advanced-settings-localization

Make the strings in "Advanced Settings" page localizable
Add FEATURE['ENABLE_GROUP_CONFIGURATIONS'] and os.environ['FEATURE_GROUP_CONFIGURATIONS'].
Merge pull request #4267 from edx/tim/feature-group-configurations

BLD-1217: Create feature flag for switching Group Configurations editing on and off
Merge pull request #4287 from louyihua/localization-cms

Missing "_()" in course_module.py
Fixes has_changes to search all the way to leaf nodes
skipping update assets, not just collectstatic, in unit tests
Add openedx-analytics discussion group to CONTRIBUTING file
Update AUTHORS
Merge pull request #4299 from edx/clytwynec/skip_update_assets_for_unittests

skipping update assets, not just collectstatic, in unit tests
Merge pull request #4302 from edx/benmcmorran/fix-has-changes

Fixes has_changes to search all the way to leaf nodes
Merge pull request #4306 from edx/db/openedx-analytics

Add openedx-analytics discussion group to CONTRIBUTING file
Hide GroupConfiguration behind feature flag in cms/templates/settings.html.
Merge pull request #4316 from edx/anton/group-experiments

BLD-1117, BLD-1217: Add read-only list of Group Configurations, Create feature flag.
User registration prevents using password as username.

Some users erroneously set their password as their username with the original layout, because the username field directly followed the password field. Users may be accustomed to the common occurrence of a password confirmation field directly following the password field.
To fix the issue, I did the following:
   - Moved the existing username and real name form fields above the password field.
   - Added a validation in the create_account handler in common/djangoapps/student/views.py, which confirms that the password field does not match the username field.

New tests created to check the added functionality.