Sends only one notification per batch review

Closes #4326

See merge request gitlab-org/gitlab-ee!8442

CE upstream - 2018-12-10 11:21 UTC

Closes gitlab-ce#54626 and gitlab-ce#54849

See merge request gitlab-org/gitlab-ee!8770

CE upstream - 2018-12-09 15:28 UTC

Closes gitlab-ce#55038 and csslab#1

See merge request gitlab-org/gitlab-ee!8768

Add endpoint to download single artifact by ref

Closes #54626

See merge request gitlab-org/gitlab-ce!23538

Populate MR metrics with events table information (migration)

Closes #41587

See merge request gitlab-org/gitlab-ce!23564

Use new reports syntax for SAST in Auto DevOps

See merge request gitlab-org/gitlab-ce!23163

Fixed styling of image comment badges on commits

Closes #54849

See merge request gitlab-org/gitlab-ce!23659

Renders feature flags link when ci/cd is disabled

Closes #8400

See merge request gitlab-org/gitlab-ee!8622

Backport operations_path helper

See merge request gitlab-org/gitlab-ce!23654

# Conflicts:
#	app/assets/javascripts/main.js
#	app/assets/javascripts/monitoring/components/dashboard.vue
#	app/assets/javascripts/notes/components/note_header.vue
#	app/assets/javascripts/user_popovers.js
#	app/assets/javascripts/vue_shared/components/user_popover/user_popover.vue
#	app/controllers/projects/environments_controller.rb
#	locale/gitlab.pot
#	spec/javascripts/api_spec.js
#	spec/javascripts/user_popovers_spec.js

[ci skip]

CE upstream - 2018-12-07 20:59 UTC

Closes gitlab-ce#54862 and gitlab-runner#3807

See merge request gitlab-org/gitlab-ee!8762

Updates specs

try to fix test

Change link for upgrades and renewals questions

See merge request gitlab-org/gitlab-ee!8753

Fix failure in spec/services/groups/autocomplete_service_spec.rb

Closes #8777

See merge request gitlab-org/gitlab-ee!8766

Epic issue list and related issue list re-design

Closes #6086

See merge request gitlab-org/gitlab-ee!8431

CE Backport: Epic issue list and related issue list re-design

See merge request gitlab-org/gitlab-ce!23658

You can't add user to subgroup with lower access level than parent group
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Resolve "Navigating unresolved discussions on Merge Request page"

Closes #51122

See merge request gitlab-org/gitlab-ce!22789