Add detailed info on storage path mountpoints

Users that run GitLab from source should be extra careful when using the
multiple repository storage feature. Make sure there is a detailed explanation
why this happens and how to overcome it.

See merge request !590

[ci skip]

Refactor repository storages documentation

Use detailed information on using the multiple repository storage feature

See merge request !589

[ci skip]

Rename Spinach::Features::AdminGitHooksSample to Spinach::Features::AdminPushRulesSample

Closes #807.

See merge request !588

Signed-off-by: Rémy Coutable <remy@rymai.me>

Refactor protected branches documentation

From CE https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5419

See merge request !585

Refactor Slack service documentation



See merge request !587

[ci skip]

Move admin application settings to own path

Move existing documentation to its own `user/admin_area/settings` path.

From CE https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5420

See merge request !586

[ci skip]

CE upstream



See merge request !584

Don't drop in DropAndReaddHasExternalWikiInProjects

## What does this MR do?

This MR fixes the migration in question so it doesn't first drop and then re-add a column.

## Are there points in the code the reviewer needs to double check?

Not really.

## Why was this MR needed?

The old migration could lead to application errors as the column would temporarily not exist between the drop column and add column statements.

## What are the relevant issue numbers?

https://gitlab.com/gitlab-com/infrastructure/issues/239

## Does this MR meet the acceptance criteria?

- [x] ~~[CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added~~
- [x] ~~[Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)~~
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5402

Add allow_failure CI documentation

## What does this MR do?

Adds documentation for the `allow_failure` keyword for the CI.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/17669

See merge request !5398

Add hints for Kerberos sign-in failure

We do not know what went wrong when this page is shown but we can guess.

See merge request !583

Dropping a column and then re-adding it can lead to the application
throwing errors as the column may temporarily not exist. To work around
this we'll reset the various project rows in batches _without_ removing
any columns.

Don't use `params[:id]` while building `markdown_preview_path`.

- Closes #20079

See merge request !5400

Use RequestStore to cache the contents of the current License

Fixes #695 

See merge request !566

Merge branch '799-viewing-a-mr-with-approvals-with-an-anonymous-user-results-in-error-500' into 'master'

Don't check if anonymous user can update MR

Closes #799. Interestingly, I think previously we showed the 'Approve MR' button to anonymous users when an MR had approvals from anyone allowed, but we didn't blow up with a 500 error.

See merge request !582

1. Instead, use `@page.title`, since it's always guaranteed to be around
   in a wiki.

2. `params[:id]` is _not_ always guaranteed to be around - if a page is
    created with errors, `render :edit` is called, and `params[:id]` is
    `nil`.

3. More context: https://gitlab.com/gitlab-org/gitlab-ce/issues/20079#note_13223240

Fix migration to make it fast

## What does this MR do?

Changing the migration introduced in !5387 so that it's fast. The idea is that the content of the `projects.has_external_wiki` is currently wrong, so we can just drop and recreate the column.

## Does this MR meet the acceptance criteria?

- [x] No CHANGELOG needed
- Tests
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5394

Signed-off-by: Rémy Coutable <remy@rymai.me>

Cast duration to integer in `TimeHelper#time_interval_in_words`

Fixes #20055.

- [x] No CHANGELOG since it fixes a regression introduced in RC12.
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5391

Fix emails on push for new and deleted branches

## What does this MR do?

Fix EmailsOnPushWorker when the push is either a new branch or a deleted branch.

## Are there points in the code the reviewer needs to double check?

Don't think so.

## Why was this MR needed? / What are the relevant issue numbers?

Closes #20061.

## Does this MR meet the acceptance criteria?

- ~~[CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added~~ (regression)
- ~~[Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)~~
- ~~API support added~~
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)


See merge request !5390

Signed-off-by: Rémy Coutable <remy@rymai.me>

Document how to upgrade from password-based Kerberos



See merge request !575

Signed-off-by: Rémy Coutable <remy@rymai.me>

Show tooltip on GitLab export link in new project page

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19993

When the project path/name is not filled, we should show a tooltip in the `GitLab export` link, plus a flash message if the user still tries to click on it.

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5363

Hide project name in project activities

## What does this MR do?

- hide namespace and project name on project activity page

## Are there points in the code the reviewer needs to double check?

- did `.event_label` have any meaning?

## Why was this MR needed?

- all events on project activity page are from the same project, so the information was redundant

## What are the relevant issue numbers?

closes #18963

## Screenshots

### Before

![events-before](/uploads/76336e3f5cb08d4ef984df73c89aa90f/events-before.png)

### After

![events-after](/uploads/4a10718ed32960efc115d7854e5cad68/events-after.png)

![after-john-activity](/uploads/d9d151a829d8d32136525e8eb7ea04ad/after-john-activity.png)


See merge request !5068

Add image border in Markdown preview

## What does this MR do?

- add image border in Markdown preview like it is show after a comment is saved
- fix margin and shade of  `<hr>` in Markdown preview

## Are there points in the code the reviewer needs to double check?

Is `.md` the right class to use?

## Why was this MR needed?

The border was missing.

## What are the relevant issue numbers?

fixes #19652

## Screenshots

### Before

![before](/uploads/683e2af7278c33d29b2a1ae19d1136e3/before.png)

### After

![after](/uploads/07dcee531a5696303cb34b4a88357e8a/after.png)


See merge request !5162

Fixed dropdown enter key when searching

## What does this MR do?

When searching in a dropdown you can now just press the enter key to trigger a click on the first row rather than having to press the down key & then enter.

## What are the relevant issue numbers?

Closes #19741 

See merge request !5231

Update doc for award emoji API

## What does this MR do?

It fixes some docs for the award emoji API.

## Are there points in the code the reviewer needs to double check?

@zj I'm assigning you since you wrote this docs.

## Does this MR meet the acceptance criteria?

~~- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added~~
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)

~~- [ ] API support added~~

~~- Tests~~

~~- [ ] Added for this feature/bug~~

  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5386

Make Service.external_wikis return only active external wikis

Fixes #20067.

## Does this MR meet the acceptance criteria?

- [x] No CHANGELOG since it fixes a RC12 regression
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5387