Fix (un)enrollment email default language

Benp/9 bokchoy shards

When one or many users are sent an enrollment or unenrollment email via
the teacher subscription form, the emails are written in the user
language. If the user has no preferred language, e.g: when the user does
not exist, the platform language is supposed to be selected. In
practice, the emails were not being translated at all.

Escape Course Name in enrolment message 

Avoid emitting play_video event during buffering

WL-276: Move microsite_configuration/templatetags/microsite.py from individual templates to static_content.html

Fixed test course rerun failing on Chrome

Redirect to login when SAML accessed without idp param

The python social auth SAML page returns a 500 response when accessed
without the 'idp' query param. It should redirect to the login page if
the param is missing.

SOL-1550

Update Peer Instruction XBlock to 0.5

mattdrayer/index-page-bokchoy: Refactor+cover Open edX LMS index page

[firefox upgrade] Replace action chain with tinymce JS.

HOL-12 HOL-29 rss_proxy djangoapp

TNL-2178

HOL-36 Allow for override of course listing in index.html

This action chain is not reliable across firefox versions (and
in fact, even on the older firefox, fails locally). Instead we
use native JS tinymce to set the content.

TE-1133 Fix to allow for serversonly /testsonly and full test modes.

Fix flaky condition for firefox 42 on subsection container block (studio)

Use the latest i18n-tools to reduce bogus problem reports

Latest translations

Set default id token expiration to 5m for Studio

MAYN-167: Bulk uploads (CSV) of manual enrollments on white labels should be performed as 'honor' modes

Un-deprecate teams setting.

Ziafazal/wl-245: multiple backend support for microsite

TNL-3803

Change broken course_modes migration to not touch the database.

Adding the declaration of the settings object to openedx.conf to be able to import it from a nicer location

Resolving quality violations

Merging dicts with the settings definition when they exist in the microsite configuration

Using a cache to improve the perfomance of quering any dictionary in the microsite definition

Ignoring the invalid-name pylint warning since the names must be kept thsi way to stay the same as the ones in django.
Removing the default dict argument as per https://docs.python.org/2/tutorial/controlflow.html#default-argument-values

Extracting the implementation of the microsite to a selectable backend.

Leaving the function startup.enable_microsites for backwards compatibilityy

Adding a database backend

Using a cache to improve the perfomance of quering any dictionary in the microsite definition.
Changed the database backend so that it extends the settings file backend and removed all the unnecessary methods.

Using the backend provider for the get_dict function

some tweeks and some initial unit tests

Using getattr as a function insteal of calling the underlying __getattr__ directly

Adding an ModelAdmin object for the microsite model in the django-admin panel

refactor enable_microsites()

consolidate/refactor some shared code

add config to aws.py and add migration files

fix tests

Changes to get the backends to run after the refactor

add archiving capabilities to microsites. Also make a few notes about performance improvements to make

fix tests

Making the query to find if microsites exist in the database faster

add ORG to microsite mapping tables and some performance improvements

allow for Mako templates to be pulled from the database

fix tests

For the database template backend the uri of the template does not use the filesystem relative path

Fixing pylint violations

Added caching of the templates stored in the database

Fixing pylint errors

fix pylint

Clearing the cache on model save

Fixing pylint errors

rebased and added test coverage

rebased cdodge/microsite-improvements branch with master and added test
coverage

added missing migration

fix quality violations

add more test coverage

mattdrayer: Add microsite_configuration to cms.INSTALLED_APPS

added microsite settings to cms/envs/test.py

run session cookie tests only in LMS

fixed broken tests

putting middleware changes back

Preventing the template_backend to be called on requests which have no microsite

changes to address feedback from mjfrey

changed BaseMicrositeBackend to AbstractBaseMicrositeBackend

changes after feedback from mattdrayer

fixed broken tests and quality violations

Allowing the backend to handle the enable_pre_startup routine

Typos and docstrings

Adressing feedback

Fixing python tests

add comment to explain why we need enable_microsites_pre_startup()