* Initialize INSIGHTS_CLOUDFRONT to null

* Put cloudfront domain under INSIGHTS_CONFIG

* Use INSIGHTS_CLOUDFRONT_DOMAIN in insights config

* Define INSIGHTS_CLOUDFRONT_DOMAIN null by default

* Set CORS_ORIGIN_WHITELIST to INSIGHTS_DOMAIN

* Add CORS header to Insights static files

* Split CORS whitelist into default and extra

* Allow HEAD, GET, OPTIONS in Insights static

* Try setting CORS Origin to $http_origin

* Use if cond to enable/disable CORS instead of map

* Missing space

* Don't initialize $cors

* Back to the old $cors_origin map

* Don't send CORS whitelist to django settings

* Replace tab with spaces

* Remove allow_all var, and update changelog

* Rename CLOUDFRONT to CDN in var name

`SUPPORT_URL` was replaced by `SUPPORT_EMAIL`

Remove setting `INSIGHTS_FEEDBACK_EMAIL`, as it was deemed redundant with `INSIGHTS_SUPPORT_EMAIL`

`DATABASE_OPTIONS` was deprecated in Django 1.2 and removed in 1.4.
`OPTIONS` should now be passed as part of `DATABASES`.

This should have been set prior to https://github.com/edx/auth-backends/pull/9 being merged. We did not catch this problem until now because the library currently used for JWT validation, pyjwt, simply skips issuer validation if the issuer is set to None.

LEARNER-693

which is used by the Learner List view's "Download CSV" button to
determine the fields to include in the CSV, and their sort order.

ECOM-4678

ECOM-4609

the extra e is for extra

The headers were pointing to the old github wiki. Since we've officially
moved to Confluence, these links should be updated.

This is needed to make use of Closure Compiler for JS minification.