to allow the HTML to be downloadable via the Course Blocks API.

Feature flag ENABLE_HTML_XBLOCK_STUDENT_VIEW_DATA must be set to enable this feature.

This app is a grab bag of init code which can't find a good home in
other apps.  This was created in response to removing lms.startup.run().

  all dirs must now go into COMPREHENSIVE_THEME_DIRS.
Move comprehensive theming setup section out of startup.py and into
  settings files using new 'derived' functionality.
Add 'derive_settings' at the end of all top-level Django settings files.
Move validation of comprehensive theming settings into new apps.py
  theming file.
Split theming code into code safe to run before settings are initialized
  -and- after settings are initialized.

This is a work in progress finished the 320px - 539px mobile
screen design.

LEARNER-2311

EDUCATOR-1448

Modifies paver webpack task to use production configuration in all
non-devstack environments, and a development config in devstack.

When edx_clear_expired_tokens command will run it will clear
all refresh,access tokens and grants expired before 2 weeks.

[LEARNER-1733]

Moves ENABLE_ENTERPRISE_INTEGRATION to settings.FEATURES,
and changes the default value to False.

* Includes custom manager.
* Includes percent validation.
* Includes useful indices.
* Subclasses TimeStampedModel

OC-3086

The module is still used by (at least) edx-enterprise.

LEARNER-2026

LEARNER-2073

EDUCATOR-171

LEARNER-2307

FEDX-375