CE-EE parity for Markdown (Banzai) feature specs

Closes #6498

See merge request gitlab-org/gitlab-ee!6249

Extract EE specific code to EE::SortingHelper

See merge request gitlab-org/gitlab-ee!7389

Moves EE-specific GFM tests (in this case, just Epic references) into
the `ee/` path.

This default will be overridden in the EE-specific subclass that uses a
different fixture path.

EE: Replace direct use of Gitlab::SQL::Union with a "from_union" method

Closes gitlab-ce#51307

See merge request gitlab-org/gitlab-ee!7384

CE upstream - 2018-09-17 15:31 UTC

Closes gitlab-ce#51093

See merge request gitlab-org/gitlab-ee!7387

Resolve "Add runner JSON schema"

Closes #51093

See merge request gitlab-org/gitlab-ce!21525

CE upstream - 2018-09-17 12:35 UTC

Closes gitlab-ce#50460, gitlab-ce#50461, #7019, gitlab-qa#323, gitlab-workhorse#181, and gitlab-org/release/framework#13

See merge request gitlab-org/gitlab-ee!7385

Add CI_JOB_TOKEN support to Maven docs

See merge request gitlab-org/gitlab-ee!7379

Backport EE changes (missing exports)

See merge request gitlab-org/gitlab-ce!21772

Backport EE changes to `app/assets/javascripts/filtered_search/issuable_filtered_search_token_keys.js`

Include correct CSS file for xterm in environments page

Closes #50956

See merge request gitlab-org/gitlab-ce!21768

# Conflicts:
#	app/models/concerns/protected_branch_access.rb
#	app/models/concerns/protected_tag_access.rb
#	changelogs/unreleased/44596-double-title-merge-request-message.yml
#	doc/user/admin_area/img/admin_area_settings_button.png
#	doc/user/admin_area/settings/continuous_integration.md
#	spec/support/helpers/stub_configuration.rb

[ci skip]

CE upstream - 2018-09-14 09:21 UTC

See merge request gitlab-org/gitlab-ee!7374

Add aws_signature_version attribute to packages config in gitlab.yml.example

See merge request gitlab-org/gitlab-ee!7375

Fix double title in merge request chat messages

Closes #44586

See merge request gitlab-org/gitlab-ce!21670

EE port: Fix double title in merge request chat messages

See merge request gitlab-org/gitlab-ee!7370

When the xterm dependency was moved to a npm dependency
the CSS file path was not updated correctly in the environments page.

In order for xterm to render properly, it needs the correct CSS path.

Merge branch '50944-unable-to-import-repository-undefined-method-import_file-for-nil-nilclass' into 'master'

Resolve "Unable to import repository:  undefined method `import_file' for nil:NilClass"

Closes #50944

See merge request gitlab-org/gitlab-ce!21765

This commit adds the module `FromUnion`, which provides the class method
`from_union`. This simplifies the process of selecting data from the
result of a UNION, and reduces the likelihood of making mistakes. As a
result, instead of this:

    union = Gitlab::SQL::Union.new([foo, bar])

    Foo.from("(#{union.to_sql}) #{Foo.table_name}")

We can now write this instead:

    Foo.from_union([foo, bar])

This commit also includes some changes to make this new setup work
properly. For example, a bug in Rails 4
(https://github.com/rails/rails/issues/24193) would break the use of
`from("sub-query-here").includes(:relation)` in certain cases. There was
also a CI query which appeared to repeat a lot of conditions from an
outer query on an inner query, which isn't necessary.

Finally, we include a RuboCop cop to ensure developers use this new
module, instead of using Gitlab::SQL::Union directly.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/51307

The class only applies to issues and not to merge requests (which are issuables, too)

Fix setup to set-up in EE-only code (Specs and a model)

See merge request gitlab-org/gitlab-ee!7349

Fix grammar (setup to set-up) in code comments, spec, views, etc. (Port CE to EE)

See merge request gitlab-org/gitlab-ee!7347

Fix grammar (setup to set-up) in code comments, spec, views, etc.

See merge request gitlab-org/gitlab-ce!21699

closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51093

Add retried jobs to pipeline stages

Closes #50461

See merge request gitlab-org/gitlab-ce!21558

Resolve "Send deployment information in job API"

Closes #50460

See merge request gitlab-org/gitlab-ce!21307

Support Kubernetes RBAC for GitLab Managed Apps for creating new clusters

Closes #29398

See merge request gitlab-org/gitlab-ce!21401

API: Allow issue weight parameter to be greater than or equal to zero

Closes #6822

See merge request gitlab-org/gitlab-ee!7335

Fixed MR widget unresolved discussions state

See merge request gitlab-org/gitlab-ce!21705