move settings validation out of startup.py

Fix polls 404 on disabled completion.

CMS urls cleanup for Django 1.11

This avoids premature registration of django checks which could break
django 1.11 startup.

This also creates a new app common_initialization in order to provide a
place to run initialization code common to both the LMS and CMS.

set a custom course_id metric on enrollment

Calling runtime.handle('progress', ...) was causing a 404 error due to
the runtime handler.  It should be okay for xblocks to submit a
completion or progress event; they just shouldn't have it treated
specially.

EDUCATOR-1642

Allow escaping out of Studio CourseOutlineXBlockModals

Import Issue.

Mailing management command cleanup for Django 1.11

Remove microsite configuration from LMS startup.py.

Move edxmako startup to AppConfig::ready.

add success component on successful form submission

Merge release back to master

Searching by course run key no longer raises an exception.

- Remove usage of django.urls.patterns
- Change urls tuples to lists
- Make all string view names callables

add option to disable capturing stderr in pytest

PLAT-1779 Fix CMS INSTALLED_APPS/model imports mismatch

A11Y Update to wiki edit field.

syncdb cleanup

Make the Section Highlights in outline a button

Edit highlights modal copy

bump enterprise version from 0.53.7 to 0.53.9

Point to the proper AppConfig in INSTALLED_APPS for course_modes.

LEARNER-2653 Added Untranslated strings files to Repo

Update translations

celery task to update sailthru purchase record

translations to transifex. This will help edx-platform
automated jenkins translation job understand when to push
translations to transifex.

Support multiple dynamic pacing experiences