add generic config for github plugin

Added django-parler configuration for django-parler

jenkins_common: Add credential id for ssh template

Deal with the case when CREATE_SERVICE_WORKER_USERS is false.

Just use the one in common that's always defined.

In this case, `service_worker_users` still needs to be defined because the when condition is applied for each item in the `{{ service_worker_users }}` list.  So that var always has to resolve.

Optional `aws` role and `EDXAPP_MYSQL_ATOMIC_REQUESTS`

Added the option of overriding atomic requests without having to override the entire database configuration structure.

Added a way to override having the aws role be installed. In cases where a local host is being used, aws role is not needed. Default remains true though.

Added the `install:configuration` tag to the step that writes the forum_env to disk so that updated mongodb credentials
are properly propagated to the service during deployments.

Add configuration for extra middleware classes

Remove jenkins_build play script override

Enable splunk and jvm args on jenkins

Fix mask_passwords template name

download specific branches of jenkins configuration

jenkins_common support masked plugins config script

Remove fake thumbnails task.

This task was required for the Ginkgo release,
but should no longer be necessary for Hawthorn.

Add Django requirements file to devstack req list.

Add new Django requirement file to install.

support increasing proxy_connect_timeout

Reverting ghprb versioning in template file

add templates for system properties script

[ENT-628] Add `ENTERPRISE_TAGLINE` and `PLATFORM_DESCRIPTION` to edxapp.