TODO: Add tests to make sure controllers and API
would tick the queue.

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/8664#note_22853522

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/8664#note_22853463

* upstream/master: (379 commits)
  Fixed failing tests because list doens't exist
  Add changelog file
  Update system_note_service_spec.rb
  Remove noteable object in time tracking system notes [ci-skip]
  Make all system notes lowercase
  Fixed eslint
  Don't render snippet actions for logged-out users
  Remove deprecated MR and Issue endpoints and preserve V3 namespace
  Removed additional dropdown list animations
  Improve docs on CI/CD code coverage regexp setting
  Improve Changelog entry for CI config compatibility fix
  Refine docs on code coverage regexp on job level
  Introduce maximum session time for terminal websocket connection
  Add Changelog entry for CI config compatibility fix
  Map configuration to directory locations and add defaults to NFS HA doc.
  Update docs on setting up a CI/CD coverage regexp
  Fix Rubocop offense in legacy CI/CD config specs
  add CHANGELOG entry for !8988
  transpile all javascript files with babel
  add npm run webpack command
  ...

Issue filters in boards modal

Closes #26205

See merge request !8903

Remove coverage entry from global CI/CD options

See merge request !8981

Adding GitLab Pages to CE

Closes #14605, gitlab-com/infrastructure#1058, gitlab-ee#1333, and #323

See merge request !8463

Rename example from file_name to file_path

Closes #27643

See merge request !8959

Add traits for ProjectFeatures to Project factory

Closes #24007

See merge request !8925

Update NFS HA doc with location -> config mapping

Closes #27685

See merge request !8993

Added specs for merge request environment list

See merge request !8937

Don't render snippet actions for logged-out users

Closes #27708

See merge request !8995

Resolve "Remove hover animation from row elements"

Closes #26863

See merge request !8842

V4 API: Remove deprecated MR and Issue endpoints and preserve V3 namespace

Closes #27180

See merge request !8967

# Conflicts:
#   db/schema.rb

Make all system notes lowercase

See merge request !8807

Modify the search bar area on admin/projects page

Closes #26794

See merge request !8776

Resolves user avatar flickers as you type

Closes #27602

See merge request !8950

Use babel to transpile all non-vendor javascript assets regardless of file extension

See merge request !8988

fix ace editor modules to include asset digest in production

See merge request !8869

Introduce maximum session time for terminal websocket connection

Closes #26263

See merge request !8413

Unify projects search by removing /projects/:search endpoint

Closes #22007

See merge request !8877

API: Fix file downloading

See merge request !8953

Store the value in application settings.
Expose the value to Workhorse.