CE-to-EE `master` for RC1

See merge request !262

Add 8.6 CE-to-EE guide

[ci skip]

See merge request !257

Prepare docs for 8.6 RC1

[ci skip]

See merge request !3173

Don't remove `ProjectSnippet#expires_at` from API

See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3103

This partially reverts commit 836d5930.

See merge request !3144

[ci skip]

Fixed tests for MR & issue filters

See merge request !3203

Remove sleeps from network graph feature spec

Also removed a double negative in the step description

See merge request !3199

Use Capybara find methods and remove sleeps in feature specs in "All Issues" filter

Fixes sporadic build failures (e.g. https://gitlab.com/gitlab-org/gitlab-ce/builds/856233)

See merge request !3198

Conflicts:

- app/services/search/global_service.rb
- app/services/search/project_service.rb
- app/services/search/snippet_service.rb
- app/views/profiles/accounts/show.html.haml

Implements upcoming filter in milstones

![Imgur](http://i.imgur.com/Oc2LZrF.png)

@DouweM @JobV I think this is what you wanted :) Lemme know if it there is something that need changing
Had alot of fun doing it!

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/14102

See merge request !3148

Redirect host check

Fixes https://dev.gitlab.org/gitlab/gitlabhq/issues/2649

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/13956

See merge request !1945

Fixes
https://dev.gitlab.org/gitlab/gitlabhq/issues/2649
https://gitlab.com/gitlab-org/gitlab-ce/issues/13956

Gitlab Geo:  Authenticate with OAuth

This changes the way Geo (#76) nodes authenticates, to remove the requirement of session sharing between nodes, as described here: #366

# Checklist

 - [x] When a secondary Geo node is created an OAuth Application is created associated to it
 - [x] When a secondary Geo node is removed the associated OAuth application is also removed
 - [x] When a user tries to login it must be redirected to the primary node using the OAuth workflow
 - [x] The user must be redirected to the "first accessed url before authentication" (as expected)
 - [x] User should be able to logout from a secondary node
 - [x] It displays authentication errors when OAuth application is not present
 - [x] It handles authentication errors when OAuth flow fails
 - [x] Solution for what to do when/if OAuth application is removed

See merge request !237

Reduce example documentation.

We should not duplicate indexes between the top level and lower level.

See merge request !3162

Revert "Revert "Merge branch 'support-go-subpackages' into 'master'""

This reverts commit 5a586f36

See merge request !3194

This reverts commit 5a586f36

Remove unnecessary go-get test (superseded by middleware)



See merge request !3193