fix sg param in packer jobs

parameterize sg for packer builds

Allow `confirm_email` & `terms_of_service` to show in extra fields.

PLAT-1614 Make Docker containers use en_US.UTF-8

Cache all static assets for 5 minutes by default?

* 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

Add check-ses-limits python script

Enable for jenkins/mongo/rabbit

remove docker-proxy-user and add jenkins user to docker group instead

update documentation to specify how to run ansible

Upgrade to latest ansible.

Changes needed to install docker on tools-jenkins.

Changelog - https://github.com/ansible/ansible/blob/devel/CHANGELOG.md

remove reference to edxops/forums and replace with edxop/forum

Install docker on tools jenkins.

Updated language code and cookie for ecommerce

Add splunk to neo4j

Remove vestiges of obsolete USE_CUSTOM_THEME setting