Add feature to do auto signup with external auth

Improve accessibility of inline discussions

Improve auth handling of Locators

Ensure user admin screen gets the union of all possibly matching group names.
Smarter default group naming.
STUD-1003

Improve calculator's tooltip accessibility.

Enabled back turned off tests.

Updated comments.

BLD-537

Merged master to rc/2013-11-21, so we can merge it back to master.

Added refund datetime info to Orders, OrderItems

Remove code related to Pearson Testing Centers

BLD-384: Add grading to LTI module

Co-author: Alexander Kryklia <kryklia@edx.org>
Co-author: Ned Batchelder <ned@edx.org>
Co-author: Oleg Marchev <oleg@edx.org>
Co-author: Valera Rozuvan <valera@edx.org>
Co-author: polesye
[BLD-384]

Co-author: Ned Batchelder <ned@edx.org>

This does not yet replace the existing per-student anonymous id, but
is intended to do so in the future.

Co-author: Alexander Kryklia <kryklia@edx.org>
Co-author: Ned Batchelder <ned@edx.org>
Co-author: Oleg Marchev <oleg@edx.org>
Co-author: Valera Rozuvan <valera@edx.org>
Co-author: polesye

Updates to depend on the latest version of XBlock, which includes
support for service-to-service (thirdparty) handler urls, which aren't
authenticated with a user (unlike handler requests coming from the
xblock client-side javascript).

Co-author: Ned Batchelder <ned@edx.org>

CSV Reporting of Shopping Cart Purchases, with tests

The show/hide toggle now properly acts like a button, and focus is now
trapped on the loading element for both the show/hide action and loading
of a new page.

This removes the use of the space key to activate buttons, which is not
expected behavior.

Disabled another video test that failed in master

Studio: FIX - Italicize in xmodule/block previews

STUD-963

Studio: FIX - correcting hiding state of notification UI for < IE9

Disabled video caption tests that failed in master

Changed unit identifier to be readonly, not disabled

Restful api for course advanced settings

Update course_navigation.html #os

STUD-948

Fix unique vertical url + add test

STUD-979