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.
This modifies the lang-pref django app to:
a) Use the current value of the 'edx-language-preference' cookie to set the
users Accept-Language header on an incoming request.
b) At the end of the request, update the 'edx-language-preference' cookie
to reflect the users current Language Preference choice, if any.
[LEARNER-542]
This feature is not well-documented, so it is unclear how to setup Elasticsearch properly to make it work. The next person who needs to work on this feature will need to make it work and, ideally, document it.
