[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.

WIP wiki support for microsite templates

Release for Jan 12, 2016

Disable Optimizely in the courseware view.

Stripping the leading / for the django_templates finder

Enabling the microsite configurations before running django.setup()

Adding only the templates directory before startup

Adding the missing overrides file at the django templates main

Using the comp_theming way of overriding css

Adding test for the microsite_template_path filter

Added tests & general message to js when parsing fails.

TNL-3989

Release Candidate rc/2016-01-12

Enable MathJax in Course Pages

Merge pull request #11125 from mitocw/ehnancement/aq/dont_allow_user_to_register_ccx_without_invitation

Hide CCX course registration from unenrolled students

Disable button while adding/removing bookmark to a unit.

Fixed test quality button works correctly in Video tests failing on C…

TNL-3968

@Revert 10648 edraak/calculator fixups

TNL-4004

Prevent course image thumbnail race condition from causing TransactionManagementError

It somehow ended up in CourseOverviewImageSetTestCase (merge artifact?).

Without this change, we'd throw a TransactionManagementError in the case
where we have a race condition and generate multiple CourseOverviewImageSets
for the same CourseOverview concurrently.

There's already a global $link-color variable defined in
lms/static/sass/base/_variables.scss. Mark the $link-color
variable in sequence scss file with !default, so that the
global $link-color variable gets used, if defined.

Add the migrations necessary for asset base URL support.

userstanding is now OneToOneField

Shrink images

HOL-18 Register form microsite override

Update translations (autogenerated message)

Revert "Add options trailing slashes to the Enrollment API."

Remove unused header_extra.html file

This reverts commit 3149aaa3.

WL-269 used gettext(...) in .underscores files.