Remove now-unused django_db_models_options.py

Rate limit course list API.

This endpoint is likely being inefficient with how it's querying various parts of the code
and can take courseware down, it needs to be rate limited until optimized.

LEARNER-5527

Code that actually used it was removed in this commit:
https://github.com/edx/edx-platform/commit/26b4e30833b0410d0131c5e7bfa40b6f418ae135#diff-8d36006736e42cad141490ae17f58a89

[edxnotes] use the correct url and update the API params

Extract course run with highest grades.

Change waffle flag for enrollment throttle to switch

This is really two separate things:

1. Fix the notes retirement endpoint to generate the correct notes API
url "/api/v1/annotations/" rather than the nonexistent "/api/v1/".

2. Update the API params to use "user" rather than "user_id".  This
depends on another PR in edx/edx-notes-api to make the corresponding
change on the API side.  This is required because "user" is the
hard-coded key that the permissions class uses to check the JWT token
user.

add script to detect dead code

Bump poll xblock version to 1.5.1 - removes warning.

[ENT-1029] edx-enterprise version bump 0.69.1

Rate limiting registration form validation end point.

This patch would ratelimit registration form validation
endpoint for anonymous user based on his/her ip.

LEARNER-3810

Revert "Switch container factory to webpack"

Add require_https to all is_safe_url calls

Change usages of is_safe_url to use new allowed_hosts instead of host

Exempt csrf on donate

Revert "OAuth2 API to call XBlock handlers"

PLAT-1746: Use Django 1.11 format_lazy instead of allow_lazy

Switch container factory to webpack

"host" parameter is deprecated and throws a warning

Remove SessionAuthenticationMiddleware from INSTALLED_APPS

Reapplies edx/edx-platform#17509

This reverts commit 0f7e2373.