Backport EE SlashCommand Refactor

See merge request gitlab-org/gitlab-ce!19177

Rails5 fix arel from

Closes #46281

See merge request gitlab-org/gitlab-ce!19340

Update to GitLab Workhorse v4.3.0

See merge request gitlab-org/gitlab-ce!19313

Add ability to search wiki titles

Closes #34526

See merge request gitlab-org/gitlab-ce!19112

Fix N+1 with source_projects in merge requests API

See merge request gitlab-org/gitlab-ce!19346

Bump gitlab-shell to 7.1.3

See merge request gitlab-org/gitlab-ce!19358

Fixed typo in commit message help popover

Closes #47060

See merge request gitlab-org/gitlab-ce!19314

Fix intermittent failing spec in spec/support/helpers/cycle_analytics_helpers.rb

Closes #43981

See merge request gitlab-org/gitlab-ce!19338

Fix attr_encryption key settings

Closes #47166

See merge request gitlab-org/gitlab-ce!19341

Fix missing squash parameter in doc/api/merge_requests.md

See merge request gitlab-org/gitlab-ce!19260

Add per-project pipeline id (Use `AtomicInternalId`)

Closes #3691

See merge request gitlab-org/gitlab-ce!18558

This includes the change that prints the @username of a user instead
of the full name.

https://gitlab.com/gitlab-org/gitlab-shell/merge_requests/204

Update IPs to valid example IPs.

Closes #47197

See merge request gitlab-org/gitlab-ce!19357

As per: https://tools.ietf.org/html/rfc5737

Resolve "URI::InvalidURIError: bad URI(is not URI?): users/xxx[bot]"

Closes #47193

See merge request gitlab-org/gitlab-ce!19354

Update selenium-webdriver to 3.12.0

Closes #47183

See merge request gitlab-org/gitlab-ce!19351

Now that we are checking `MergeRequest#for_fork?`, we also need
the source project preloaded for a merge request.

There was a race condition in the spec where if the commit is created on disk
within a second of the frozen `Timecop` time, the test fails.

Closes #43981

Fix missing key change in 20171124104327_migrate_kubernetes_service_to_new_clusters_architectures.rb

attr_encrypted does different things with `key` depending on what mode you are using:

1. In `:per_attribute_iv_and_salt` mode, it generates a hash with the salt:
https://github.com/attr-encrypted/encryptor/blob/c3a62c4a9e74686dd95e0548f9dc2a361fdc95d1/lib/encryptor.rb#L77.
There is no need to truncate the key to 32 bytes here.

2. In `:per_attribute_iv` mode, it sets the key directly to the password, so
truncation to 32 bytes is necessary.

Closes #47166

# Conflicts:
#	doc/user/project/clusters/index.md

Fix bootstrap 4 file inputs

Closes #46701

See merge request gitlab-org/gitlab-ce!19333

Add comment about the need for truncating keys in Ruby 2.4

See merge request gitlab-org/gitlab-ce!19330