TNL-3803

Allow certificates with 'auditing' status to be regenerated.

Crush down images.

There's a test to ensure users can't upload too large of a profile picture, so the picture was too small to trigger that behavior, and now fails.  This just returns the image to its original size.

This reverts commit 8402be3b.

Ran these suckers through ImageOptim, which crunched 'em down real nice.

ECOM-3401

Fixed test annotation component failing on Chrome

Provide useful response messages with access token errors

Format responses as a JSON dict containing an error_code and a
developer_message.  user_message is not necessary, as these are API
level errors, not seen by end users.

MA-1900

Create a new bok-choy DB cache

Clear out the bok choy DB with reset_db, not flush

[wip] Mark GeneratedCertificate records for audit mode as not eligible for a certificate.

An `eligible_for_certificate` field is added to the
GeneratedCertificate model. This way we can retain existing grading
logic, as well as maintaining correctness in analytics and reporting.

Ineligible certificates are hidden by using the
`eligible_certificates` manager on GeneratedCertificate. Some places
in the coe (largely reporting, analytics, and management commands) use
the default `objects` manager, since they need access to all
certificates.

This commit also updates the DB cache for acceptance tests.

HOTFIX Release for Jan 12, 2016

HOTFIX 2016-01-12

Mark sequence link-color scss variable default.