The course now includes a read-only name attribute.

XCOM-536

Remove remove_input_state.py, as it was one-time fix code, and is not worth porting to the new interface

This required the following changes to the DjangoXBlockUserStateClient
semantics:

1) Changes get/get_many to return XBlockUserState tuples, rather
than state dictionaries or (block_key, state) tuples.
2) Raises DoesNotExist if get_history is called on an XBlock that has
had no data saved to it.
3) Returns XBlockUserState tuples as the results of get_history.

enrollments.

The goal for this PR is to have a single mechanism for registering users and
reducing the number of places where special-casing for ccx courses is needed. The
migration at this point is purposefully limited to convert ccx memberships into
student enrollments when moving forward. No backward migration is in place at the
moment. The ccx membership tables are not removed at this time. It is possible to go
backwards and forwards multiple times with no errors or data loss.

TNL-2677

TNL-2864

This reverts commit 948f652c.

ECOM-1917

There's an "explicit" way to configure Django Debug Toolbar that isn't
prone to circular import errors:

http://django-debug-toolbar.readthedocs.org/en/1.0/installation.html#explicit-setup

Do that.

XCOM-497

The Commerce API now sets the correct display name for known course modes, but continues to default to the mode slug for unknown course modes.

Discussion API for thread sorting now takes the sort_by
parameter for the sort key such as by comment_count or
vote_count. Also takes the sort_direction parameter for
sorting the thread results.

TNL-2892

This test failed on master because it saw "Loading" and did not wait.

No need to go through Mako