Merging Patch Release 2016-06-15 back to master

A more considerate outer_atomic.

A named outer is suitable when dealing with IntegrityErrors. It only
checks that it is not nested under an atomic only if it is nested
under enable_outer_atomic(name=<name>). This way only the view which
is causing IntegrityErrors needs to have its automatic transaction
management disabled and other callers are not effected.

Changed refund log level to warning.

ECOM-2378

AC-455 adding main to PDF books; styling chapters

Patch Release 2016-06-15

Merge Release to Master

Don't try and cleanup a directory that doesn't exist (in badging tests)

Release Candidate rc/2016-06-14

Can't report or vote for your own posts

Added support for OpenID Connect single logout

In addition to logging the user out of LMS, the logout view also logs users out of the IDAs to which they previously authenticated.

ECOM-4610

Revert "Revert Adding logic to check if cert is invalidate then user cannot see the cert"

HULL-22 Get platform name via microsite configuration for forgot password page

ECOM-4217

Test marked as flaky

[PERF-325] Add versioned course asset URLs when canonicalizing asset paths.

Fix remove user from cert-exception list

Merge pull request #12714 from edx/tasawer/bugfix/ecom-1730-fix-integrity-error-in-student-enrollment

Fixed IntegrityError when making parallel enrollment requests for the same user / course

ECOM-1730

HULL-22 Get platform name via microsite configuration for forgot password page

AC-472 removing outline from main

make error message more readable

Fix order history page if order doesn't have any product

Don't hide spans within ui-btn-non class.

Pin the specific version number so the github install knows when to run.

Revert "Adding logic to check if cert is invalidate then user cannot see the …"