This moves all instances of `prepend EE::Something` and `include
EE::Something` in models to the last line of the corresponding model.
This pushes EE specific code further down the files, reducing the
likelihood of developers running into merge conflicts.

Moving this method to a separate module looks a bit odd, but it allows
for EE to extend the method without also having to redefine a variety of
validation rules.

`Mentionable::ReferenceRegexes` used to define the following two
constants:

1. DEFAULT_PATTERN
2. EXTERNAL_PATTERN

These two constants were built using some of the class methods that
reside in this same module. In EE we redefine one of these methods by
using `prepend` at the start of the `ReferenceRegexes` module. This
poses a problem: we can not move the `prepend` to the end of the file,
because the constants later on depend on it.

To resolve this problem, this commit turns these constants into class
methods that memoize their results. This allows EE to redefine the
appropriate methods before these two class methods are used, in turn
allowing us to move the `prepend` to the end of the file.

See https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/8198 for more
information.

Disable usage pings in review apps

See merge request gitlab-org/gitlab-ee!8354

CE upstream - 2018-11-12 09:21 UTC

See merge request gitlab-org/gitlab-ee!8397

Merge branch 'ee-53082-gitlab-ce-11-4-0-gemfile-conflict-gitlab-markup-and-github-markup' into 'master'

Update gitlab-markup gem to avoid binary name collision

See merge request gitlab-org/gitlab-ee!8393

CE upstream - 2018-11-12 00:21 UTC

See merge request gitlab-org/gitlab-ee!8394

Resolve conflicts for https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/8394

Update URLs to better ones

See merge request gitlab-org/gitlab-ce!22931

Fix link for raising helm chart issues

See merge request gitlab-org/gitlab-ce!22970

Add link in K8s integration docs to RBAC roles

See merge request gitlab-org/gitlab-ce!22941

# Conflicts:
#	doc/ci/examples/deployment/composer-npm-deploy.md
#	doc/development/documentation/styleguide.md

[ci skip]

Docs: Update Variable naming - EE Port

See merge request gitlab-org/gitlab-ee!7921

Docs: Update Variable naming

See merge request gitlab-org/gitlab-ce!22352

See https://gitlab.com/gitlab-org/gitlab-ce/issues/53082

CE upstream - 2018-11-11 17:21 UTC

See merge request gitlab-org/gitlab-ee!8392

Fix error handling bugs in kubernetes integration

See merge request gitlab-org/gitlab-ce!22922

CE upstream - 2018-11-09 23:30 UTC

Closes gitlab-org/release/framework#48 and gitlab-ce#53773

See merge request gitlab-org/gitlab-ee!8389

# Conflicts:
#	app/views/clusters/clusters/_sidebar.html.haml
#	lib/gitlab/background_migration/redact_links.rb
#	locale/gitlab.pot

[ci skip]

Use gitlab-ui in jobs and pipelines

See merge request gitlab-org/gitlab-ce!22782

EE: User can create a group level cluster and install applications

See merge request gitlab-org/gitlab-ee!8080

Remove circular dependency on Redactable in migration

See merge request gitlab-org/gitlab-ee!8387

Remove circular dependency on Redactable in migration

See merge request gitlab-org/gitlab-ce!22951

Resolve "GitLab Pages settings regressions"

Closes #48475

See merge request gitlab-org/gitlab-ce!22821

Updates clipboard button with gitlab-ui

See merge request gitlab-org/gitlab-ce!22923

Gitlab::BackgroundMigration::RedactLinks was prepending
EE::Gitlab::BackgroundMigration::RedactLinks, while
EE::Gitlab::BackgroundMigration::RedactLinks was trying to include
Gitlab::BackgroundMigration::RedactLinks::Redactable. Ruby 2.5.3 failed
with an uninitialized constant
(https://gitlab.com/gitlab-org/gitlab-ee/-/jobs/118388511).

Gitlab::BackgroundMigration::RedactLinks was prepending
EE::Gitlab::BackgroundMigration::RedactLinks, while
EE::Gitlab::BackgroundMigration::RedactLinks was trying to include
Gitlab::BackgroundMigration::RedactLinks::Redactable. Ruby 2.5.3 failed
with an uninitialized constant
(https://gitlab.com/gitlab-org/gitlab-ee/-/jobs/118388511).

Fix alignment of diff comment buttons

Closes #53768

See merge request gitlab-org/gitlab-ce!22944