CE upstream - 2018-05-01 18:25 UTC

Closes #4922

See merge request gitlab-org/gitlab-ee!5535

# Conflicts:
#	app/helpers/auth_helper.rb
#	doc/api/discussions.md
#	lib/api/discussions.rb
#	spec/helpers/auth_helper_spec.rb
#	spec/requests/api/discussions_spec.rb

[ci skip]

Fix memory and performance issues in Karma test suite

Closes #45900 and #45806

See merge request gitlab-org/gitlab-ce!18658

Fix repository location in GitLab QA squash specs

See merge request gitlab-org/gitlab-ee!5528

Bump nokogiri to 1.8.2 in qa Gemfile

See merge request gitlab-org/gitlab-ce!18673

Use gitaly 0.96.2

See merge request gitlab-org/gitlab-ce!18670

CE upstream - 2018-05-01 00:27 UTC

See merge request gitlab-org/gitlab-ee!5524

Fix commit trailer rendering when Gravatar is disabled

Closes #45633

See merge request gitlab-org/gitlab-ce!18586

Resolves CVE-2017-18258

Use gitlab-workhorse 4.2.0

See merge request gitlab-org/gitlab-ce!18671

Use persisted diff data instead fetching Git on discussions

Closes #44052

See merge request gitlab-org/gitlab-ce!18657

Resolve "Remove USE_SYSTEM_GIT_FOR_FETCH"

Closes #5224

See merge request gitlab-org/gitlab-ee!5525

Minor fix of disaster recovery doc

See merge request gitlab-org/gitlab-ee!5518

Add alpine mirrors while operating on k8s cluster

Closes gitlab-ee#4922

See merge request gitlab-org/gitlab-ce!18651

Resolve "Geo: Prometheus metrics for checksummed/verification is confusing"

Closes #5466

See merge request gitlab-org/gitlab-ee!5367

Merge request and commit discussions API

Closes #20901

See merge request gitlab-org/gitlab-ce!18537

[EE] Discussion API for merge requests and commits

See merge request gitlab-org/gitlab-ee!5469

Use Ruby methods, not Rails' String#first

See merge request gitlab-org/gitlab-ce!18669

[CE] Exclude LDAP from OmniauthCallbackController base methods

See merge request gitlab-org/gitlab-ce!18619

Exclude GroupSAML from sign in buttons

See merge request gitlab-org/gitlab-ee!5449

show only groups an admin is a member of in dashboards/grops

See merge request gitlab-org/gitlab-ce!17884

Gitaly-Ruby is not a Rails application, which made the method not exist
after the vendor. This patch uses direct indexing, which has the same
properties that `#first` has.

Found while working on: https://gitlab.com/gitlab-org/gitaly/merge_requests/699

Update timeline icon for description edit

Closes #39946

See merge request gitlab-org/gitlab-ce!18633

Fix spec/features/projects/issues/user_toggles_subscription_spec.rb

Closes #45918

See merge request gitlab-org/gitlab-ce!18666