I'll put it in configuration later, but why didn't we allow this years
ago?  The goal is to store the data dir in /edx/var/edxapp not in
/edx/app/edxapp.

It looks like this was part of the original rollout of the microsites
feature back in December 2013 [1], but was quickly removed in February
2014 [2]. These references have been orphaned ever since.
I can find no other references to it in the platform, save these.

[1] a3211a74
[2] aa43689a

Change from specifying a retired username/email format to specifying
  a retired username prefix and a retired email prefix/domain,
  preventing possible config errors due to unexpected/bad formats.

- Methods for getting hashed retired users and usernames
- A DRF permission for retiring users

This is required due to the way we run migrations, starting with cms.

Update the VideoModule to publish a completion event when the player
reaches 95% complete, and submit a BlockCompletion when that event
occurs.

OC-3091
MCKIN-5897

In the absence of an EDX_PLATFORM_VERSION OS env variable, we used to
calculate the current version by looking at the current git revision of
the edx-platform repo. This was an expensive calculation (~7% of startup
costs). It also turns out that at some point we stopped setting that env
variable anywhere, so it always fell back to recalculating it.

With this commit, we'll start reading the code version from the env JSON
files, and fall back to "unknown" rather than doing the dealer.git call.

Add accessibility accomodation request page to studio and link to said page in footer, both behind a Waffle switch. Add tests for the new page.

The LMS and edx-enterprise currently communicate via REST APIs, even
though they are all running within the same service.

Currently API URLs are constructed using LMS_ROOT_URL, but that is
problematic on some systems where the external LMS_ROOT_URL is not
accessible from the private network, or routing internal requests via
the external URL is not desireable.

This patch introduces a new setting variable LMS_INTERNAL_ROOT_URL which
defaults to the value of LMS_ROOT_URL for backwards compatibility.

The LMS and edx-enterprise will use LMS_INTERNAL_ROOT_URL to construct
API URLs instead of LMS_ROOT_URL.

  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.

EDUCATOR-565 | Add POLICY_CHANGE_GRADES_ROUTING_KEY, fix errors in compute_all_grades_for_course circuitry.

move tasks into tasks.py

add more logging