Add app_label to models to prevent Django1.9 warnings.

WIP: Lots of Python unittest speedups

Fixed progress exception for credit courses

Speed up comment client tests

Also accelerates forums UnicodeTestCases

Remove multiple course export format versions.

Don't hardcode student_module_history

Use SharedModuleStoreTestCase in the courseware navigation tests for speedup.

Whittling away at XML modulestore code

Add SharedModuleTestCase to git_import tests

aws_migrate may be used on boxes where that DB does not yet exist.

Check both url and title for the presence of code

Monkey patch django.db.models.options for faster cache expiry

Unit test speedups - Add context manager to SharedModuleStoreTestCase.

Ensuring page is loaded belongs in the page object.

AC-328 adding UXPL classnames to headings

Speed up course listing tests

for use when a test class has a setUpTestData() method which uses
variables set up in the setUpClass() method.
Change base teams API test class to use the context manager.

Wrap whole test with several publish/unpublish in same bulk_op.

Document use of --disable-migrations flag

This test was creating 500 courses in about 2.5 minutes. Creating 10 courses instead allows the test to execute in 7 seconds.

Student Module History Extension

This now correctly migrates and dumps files for both databases.

Run lettuce migrations for both databases

This abstract class contains most of the fields (aside from the id and
foreign key to StudentModule that the subclasses need to manage).  It
also provides a get_history method that abstracts searching across
multiple backends.

Move router code to openedx/core
We need to use it from cms and lms.
Ensure aws_migrate can be used for migrating both the lms and cms.

Handle queries directed to student_module_history vs default and the
extra queries generated by Django 1.8 (SAVEPOINTS, etc).

Additionally, flag testing classes as multi_db so that Django will
flush the non-default database between unit tests.

Further decouple the foreignkey relation between csm and csmhe

When calling StudentModule().delete() Django will try to delete CSMHE
objects, but naively does so in the database, not by consulting the
database router.

Instead, we disable django cascading deletes and listen for post_delete
signals and clean up CSMHE by hand.

Add feature flags for CSMHE
One to turn it on/off so we can control the deploy.
The other will control whether or not we read from two database tables
or one when searching.

Update tests to explicitly use this get_history method rather than
looking directly into StudentModuleHistory or
StudentModuleHistoryExtended.

Inform lettuce to avoid the coursewarehistoryextended app

Otherwise it fails when it can't find features/ in that app.

Add Pg support, this is not tested automatically.

This is a clone (copy) of CSMH's declaration and methods with an added
id of UnsignedBigInAutoField

We should be able to delete the save_history code, but needs testing.

Add error logging when capa failures happen

Put StudentModuleHistory into its own database

Bump out the primary key on CSMHE

This gives us a gap to backfill as needed.
Since the new table's pk is an unsigned bigint, even for people who don't
consolidate CSMH into CSMHE, the lost rows are unlikely to matter.

Remove StudentModuleHistory cleaner

Update migrations setup during Python unit tests

Display studio name properly on empty course page.

Revert "Registration: don't require terms of service if checkbox is hidden"