This hardcoded the db_alias fetched from schema_editor and forces django
to try and migrate any second database you use, rather than routing to
the default database.  In testing a build from scratch, these do not
appear needed.

Using using() prevents us from using multiple databases behind edxapp.

Additionally - add back a removed backwards migration from certificates
0003.  I have no idea why this was dropped in the 1.8 upgrade.

Please note that this is a squshed commit and the work of:
Symbolist, macdiesel, nedbat, doctoryes, muzaffaryousaf and muhammad-ammar

Also remove useless docstrings where they were added to keep pylint
quiet.

fixed snapshot functionality for RestrictedCrouse embargo, select_related is now passed the proper hint. TNL-3452

XCOM-518

Also, I replaced a number of tearDown methods with addCleanup instead.
And also remove some unneeded patch.stopall() calls.

Celery requires all tasks to be in a tasks module. Also, the task has been updated to use default values if the the course structure generator encounters a block without the graded or format fields.

This commit fixes a bug that could occur when GeoIP
returns a continent code ("EU" or "AN") instead of a
country code.  The previous implementation would
block users in this case since the country code
was not on the whitelist (consisting of all known
country codes).  The new implementation allows user
access by default if we don't recognize the country code.

The new "country access" implementation replaces the old
implementation.  Middleware and tests have been updated
accordingly, but deprecated models are preserved
for backwards compatibility.

Add history table for course access rule changes.

Provide test utility for simulating restricted access.

Provide `redirect_if_blocked` method for integration with other
parts of the system (will be used for blocking enrollment).

Add info-level logging explaining when and why users are blocked.

The previous version of this migration incorrectly handled
disabled configuration.  When configuration is disabled,
the embargoed country field was the empty string; calling
str.split(",") produced a list with a single empty list entry,
which is not a valid country code.

Add Django admin UI for configuring country access

Migrate existing embargo rules into the new tables.

ECOM-996: updated the middleware to use new models and access rules

ECOM-996: added the flag to support old and new formats

ECOM-996: added the api layer for country access settings

ECOM-996: added the api layer for country access settings

ECOM-996 implementing the white and blacklist checks.

ECOM-996 minor re-factoring in api.

ECOM-996 minor re-factoring in api.

ECOM-1025 refactoring the code according to PR feedback.

ECOM-1025 refactoring the code according to PR feedback.

ECOM-1025 deleting cache in model save and delete methods

ECOM-1025 adding basic api test cases file.

ECOM-1025 refactoring the code according to PR feedback.

ECOM-1025 refactoring the code according to PR feedback.

ECOM-1025 refactoring the code according to PR feedback. adding the test cases.

ECOM-1025 removing extra line

ECOM-1025 removing un-used function.

ECOM-1025 removing un-used function.

ECOM-1025 re-factor the code.

ECOM-1025 re-name the test file to test_middleware_access_rules.py. we already had old test_middleware.py

ECOM-1025 adding test cases for newly added models.

ECOM-1025 adding test cases and resolve conflicts.

ECOM-1025 fixing the quality and pep-8 issues.

ECOM-1025 re-factoring the code according to the PR feedback.

ECOM-1025 re-name the variable name.

ECOM-1025 removing the _check_ip_lists and its test cases. also added few missing scenarios test cases.

ECOM-1025 removing un-used line.

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]

Move default country access messages out of static_templates, so they are not served by other Django views.

Add Django admin UI for configuring country access

Migrate existing embargo rules into the new tables.

ECOM-963

update copy in tests

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

This reverts commit 371dfd61.

This reverts commit a03baee2, reversing
changes made to 12e2d442.