The existing pattern of using `override_settings(MODULESTORE=...)` prevented
us from having more than one layer of subclassing in modulestore tests.

In a structure like:

    @override_settings(MODULESTORE=store_a)
    class BaseTestCase(ModuleStoreTestCase):
        def setUp(self):
            # use store

    @override_settings(MODULESTORE=store_b)
    class ChildTestCase(BaseTestCase):
        def setUp(self):
            # use store

In this case, the store actions performed in `BaseTestCase` on behalf of
`ChildTestCase` would still use `store_a`, even though the `ChildTestCase`
had specified to use `store_b`. This is because the `override_settings`
decorator would be the innermost wrapper around the `BaseTestCase.setUp` method,
no matter what `ChildTestCase` does.

To remedy this, we move the call to `override_settings` into the
`ModuleStoreTestCase.setUp` method, and use a cleanup to remove the override.
Subclasses can just defined the `MODULESTORE` class attribute to specify which
modulestore to use _for the entire `setUp` chain_.

[PLAT-419]

OPEN-307

OPEN-307

OPEN-307

Move modulestore config for tests to an importable location
Disable pylnt warning for lms imports in common tests
Refactor all testcases that loaded all xml courses
TE-610
TE-489

Feature flagged. Puts a checkbox in the iframe. The iframe uses an organization_full_name parameter forwarded from Drupal by the courseware views and POSTs an email_opt_in parameter to the student views, preserving it on 403.

only redirect to dashboard if user has course enrollments, otherwise remain on the course catalog page (aka homepage or root)

update lettuce test to match new expected behavior

add Jason's feedback

only apply new redirect logic for microsites

switch to use a feature flag to determine whether to support redirect behavior

Putting the new edx header behind a feature flag.

LMS-6622

Conflicts:
	cms/djangoapps/contentstore/views/tests/test_container_page.py
	common/djangoapps/external_auth/tests/test_shib.py
	common/djangoapps/student/tests/test_login.py
	common/lib/xmodule/xmodule/modulestore/tests/django_utils.py
	common/lib/xmodule/xmodule/modulestore/tests/factories.py
	common/lib/xmodule/xmodule/modulestore/xml_importer.py
	lms/djangoapps/branding/tests.py
	lms/djangoapps/courseware/tests/test_submitting_problems.py
	lms/djangoapps/courseware/tests/test_video_handlers.py
	lms/djangoapps/instructor_task/tests/test_base.py
	lms/djangoapps/instructor_task/tests/test_integration.py

Refactor get_parent_locations STUD-1663

LMS-2719

STUD-600

Caution! This is backwards incompatible

catch additional FEATURE['ENABLE_MKTG_SITE'] checks and make sure MicrositeConfigurations will override the global setting

one more faulty login regarding ENABLE_MKTG_SITE=true situations

Introduction of the Microsite feature which allows for limited multi-tenant branding on a subdomain basis, e.g. foo.edx.org and bar.edx.org

fix errorenous logic when running a microsite that could reside in a hosting environment with a marketing site in front of it

pep8/pylint fixes

address PR feedback, remove underscore from test hostname

more pep8/pylint cleanup. Skip test_microsites test, it works on localdev, not on Jenkins. Need to talk with QA team

manually add Ned's single-to-double quote fix

change aws.py runtimes so that the microsite_dir that is read from configuration is changed to a python path

Conflicts:
	lms/templates/help_modal.html

LMS-1584

Replaced existing test_none_user_index_access_with_startdate_fails
test with new test now that the tested function has changed and
was causing the original test to fail.