Port of ee-183-common-code-backport to EE

See merge request gitlab-org/gitlab-ee!4860

Projects and MRs Approvers API

Closes #183

See merge request gitlab-org/gitlab-ee!4636

CE upstream - 2018-03-06 15:24 UTC

Closes gitaly#1056, gitaly#1059, and gitlab-com/gitlab-docs#154

See merge request gitlab-org/gitlab-ee!4858

Fixes and enhancements for Geo admin dashboard

Closes #4658, #4864, and #4493

See merge request gitlab-org/gitlab-ee!4536

Add labels support to Epics

Closes #3727 and #4032

See merge request gitlab-org/gitlab-ee!4773

allow changing of approval related configuration as well as adding and
removing approvers and approver groups for both Projects and MRs

Resolve "Repository mirroring should notify when failed"

Closes #1123

See merge request gitlab-org/gitlab-ee!4699

Port to EE "Add archive feature to trace"

See merge request gitlab-org/gitlab-ee!4776

EE PORT Bring one group issue board to CE

See merge request gitlab-org/gitlab-ee!4606

Unify lib/api/merge_requests.rb between CE and EE

See merge request gitlab-org/gitlab-ee!4404

[ci skip]

Docs guidelines: cherry-picking commits from CE to EE

See merge request gitlab-org/gitlab-ee!4729

Fixes broken link on gitlab-ci-yaml include documentation

See merge request gitlab-org/gitlab-ee!4856