Add support for variables expression regexp syntax

Closes #43601

See merge request gitlab-org/gitlab-ce!18902

Do not allow to trigger manual actions that were skipped

Closes #42589

See merge request gitlab-org/gitlab-ce!18985

Add anchor for incoming email regex, closes 44989

See merge request gitlab-org/gitlab-ce!18917

Add doc about backup-restore in docker and k8s

Closes gitlab-org/distribution/team-tasks#87

See merge request gitlab-org/gitlab-ce!18702

Resolve "Expand API: Render an arbitrary Markdown document"

Closes #19861

See merge request gitlab-org/gitlab-ce!18926

Bring CE-EE parity to app/services/milestones/base_service.rb

See merge request gitlab-org/gitlab-ce!19018

Bring CE-EE parity to app/services/lfs/unlock_file_service.rb

See merge request gitlab-org/gitlab-ce!19017

Update EE > CE downgrade service removal steps

Closes #46441

See merge request gitlab-org/gitlab-ce!19034

Loosen the matcher in the MR creation test

Closes gitlab-qa#245

See merge request gitlab-org/gitlab-ce!19012

Fix api_json.log not always reporting the right HTTP status code

See merge request gitlab-org/gitlab-ce!19028

As described in https://github.com/aserafin/grape_logging/issues/45, if
a Grape error is caught by the handlers and a different return code
is returned, then the api_json.log would have a 500 error code
instead of the right value. Inserting the GrapeLogging middleware
after the Grape middleware fixes this problem.

Seen in https://gitlab.com/gitlab-com/infrastructure/issues/4249

Resolve "Web IDE: Previewing Markdown in Firefox doesn’t show a scroll bar"

Closes #45934

See merge request gitlab-org/gitlab-ce!18992

Add Keyboard shortcuts for "Kubernetes" and "Environments"

Closes #46427

See merge request gitlab-org/gitlab-ce!19002

Move API group deletion to Sidekiq

See merge request gitlab-org/gitlab-ce!18626

add specific details related to how the UX team uses labels to tackle issues

See merge request gitlab-org/gitlab-ce!18927

fix / assigne username wrapping problem has been fixed

See merge request gitlab-org/gitlab-ce!18986

NestingDepth (level 5) in pages/pipelines.scss

See merge request gitlab-org/gitlab-ce!18830

Fix group lists visual

See merge request gitlab-org/gitlab-ce!19010

Conditionally enable deprecation log messages

Closes #46158 and gitlab-com/infrastructure#4228

See merge request gitlab-org/gitlab-ce!18997

Resolve "Estimating a large amount results in a server error 500"

Closes #46193

See merge request gitlab-org/gitlab-ce!18964

Resolve "Dropdown actions in mini pipeline graph in mr widget don't work"

Closes #46381

See merge request gitlab-org/gitlab-ce!18976

Fix: Use case in-sensitive ordering by name for groups

See merge request gitlab-org/gitlab-ce!18553

[CE]  Resolve "Extract EE specific files/lines for some controllers"

See merge request gitlab-org/gitlab-ce!18994

* Reset p bottom margin for group lists to fix vertical alignment
* Remove double border for group lists to be consistent with project
lists
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Improve performance of Projects::PipelinesController#index

See merge request gitlab-org/gitlab-ce!18427

* master: (40 commits)
  Add changelog
  Update quick_start_guide.md
  Resolve "Opening Project with invite but without accepting leads to 404 error page"
  Respect the inheritance chain between Ci::Build and CommitStatus
  Remove unneccessary imports
  fixed copy to cliboard button in embedded snippets
  Fix Error 500 viewing admin page due to statement timeouts
  Grant privileges after database is created
  Only setup db in the first checkout!
  Project Sidebar: Split CI/CD into CI/CD and Operations
  Fix GPM content types for Doorkeeper
  Workhorse to send raw diff and patch for commits
  Refactor out duplication in runner_policy.rb
  Remove unnecessary runner.is_shared? checks in api because they are handled by policy
  Allow admin to assign shared runner to project through API
  Change policy list_runner_jobs -> read_runner
  Rename User#ci_authorized_runners -> ci_owned_runners
  Improve efficiency of authorized_runner policy query
  Use can? policies for lib/api/runners.rb
  Allow group runners to be viewed/edited in API
  ...