cleanup of instructor dash membership

Augment user API to allow easier access to user preferences

The endpoint includes the key of the desired preference in the URL and
returns the list of users for whom the preference is set (regardless of
the value).

Generalize grade report to allow display of any report

Add a missing comment documenting the changes done in PR 2841.

Course Image and Dates documentation changes

stud-1272

Put language modal in alphabetical order LMS-2302

Make course_id a required arg to split.create_course

We would like to be able to generate arbitrary reports and expose them to the instructor by simply uploading them to S3.  The existing grade download infrastructure pretty much supported that already, however, all of the internal and external structures were referring to the reports as exclusively grading related.

Fixes: AN-590

Merge pull request #2859 from edx/waheed/stud1404-accidental-click-can-lose-work-on-adding-new-update

Don't close modal on click outside new course update modal.

Fixed course update css to match changed tags

STUD-1404

Fix Firefox YouTube default Flash mode

BLD-895

Fixed module urls creation in legacy instructor dashboard.

remove old version of codemirror css, to prevent confusion

adjusted visual styling for editing state of xblocks, html, and video co...

adjusted visual styling for editing state of xblocks, html, and video components which had extra padding applied to it from the container page xblock styling
STUD-1410

Merge release from 2014-03-10

Conflicts:
	cms/envs/common.py
	lms/envs/common.py

Cale/fix crazy items error

Save language preference on account creation

This is necessary to allow non-browser-based services (e.g. notifier)
to know a user's preferred language even if the user has not explicitly
selected one.

Put language modal in alphabetical order LMS-2302

Without this, the new 'items' field in the course_info xmodule caused
bizarre behavior. If you added the text 'items' to a course_info
section, then the LMS would throw a 500, because the field name isn't
'data', but the stored data is a string, leading to the check of
`key.field_name in self._data`, where key.field_name is the string 'items',
and self._data is the content string.

fix capa textline display to leave "inline" alone upon status change

fix capa textline to properly use inline if specified when using math preprocessor

LMS-2327