Send ajax request for label update only if they are changed

## What does this MR do?

At the moment we send requests to update the labels on issue even if nothing has been changed. This fixes that and only sends requests when something has actually been changed.

The code gets the initial selected values based on the inputs & then compares that to the selected values when submitting. If they are equal, then no request is sent.

## What are the relevant issue numbers?

Closes #19472 

See merge request !5071

Fixes issue with rails reserved keyword type exporting/importing services.

The attribute `type`in services was being ignored by Import/Export. Added `type` as a method call in the export, as `type` gets ignored invoking `to_json`, manually adding this as a method in `import_export.yml` solves the problem.

On a different note, I found assigning a title directly to `CustomIssueTrackerService` didn't play very well with `prop_accessor`:

```ruby
> CustomIssueTrackerService.new(title: 'asdf')
NoMethodError: undefined method `[]=' for nil:NilClass
> CustomIssueTrackerService.new(title: nil)
NoMethodError: undefined method `[]=' for nil:NilClass
```

This was also causing the Import/Export to failed... So I added a custom setter that fixed the problem.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/22461

See merge request !6499
Conflicts:
	spec/lib/gitlab/import_export/project_tree_restorer_spec.rb

Fix snippets pagination

## What are the relevant issue numbers?

Closes #22500

See merge request !6500

Fixed list issues not loading with spaces in filtered values

## What does this MR do?

Vue resource is very kindly encoding our URL params when sending. However - we didn't actually want the `+` to be encoded because Rails reads that as a space, but doesn't read the encoded value as a space 😕 

This converts the `+` into spaces 👍 

## What are the relevant issue numbers?

Closes #21920

See merge request !6258

Replace deprecated Devise helper with new helper

Closes #22357

See merge request !6462

Added v-cloak to resolve disc button

## What does this MR do?

Adds `v-cloak` to the `Resolve discussion` button to avoid handlebar syntax displaying before the component compiles.

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

## Why was this MR needed?

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [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
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] 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)

## What are the relevant issue numbers?


Closes #22640

See merge request !6528

Fix Import/Export milestone and 1to1 models issue

Fix 1to1 relations on project failing to be importing and milestone ordering issue.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/22585

See merge request !6521
Conflicts:
	spec/lib/gitlab/import_export/project_tree_restorer_spec.rb

Fix IssuesController#show degradation including project on loaded notes

See merge request !6540

Fix pipelines table headers

## What does this MR do?

Removed stages loop for a single 'Stages' header.

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

## Why was this MR needed?

The headers were messing the table up. Note the redundant headers and squished cells.

![Screen_Shot_2016-09-27_at_14.40.51](/uploads/331b08c30a4af59cefc460ab4f3c2a61/Screen_Shot_2016-09-27_at_14.40.51.png)

## Screenshots (if relevant)

![Screen_Shot_2016-09-27_at_14.39.04](/uploads/687895e9152d4fe8d8f3bfc1233af39b/Screen_Shot_2016-09-27_at_14.39.04.png)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [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
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] 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)

## What are the relevant issue numbers?


Closes #22472

See merge request !6542

Be nice to Docker Clients talking to JWT/auth

## What does this MR do?

Makes all errors returned by JWT endpoint to be docker-compatible.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/22465

See merge request !6536

Fixed search dropdown labels not displaying

## What does this MR do?

Returns the search controller method after finding the project & group.

## Why was this MR needed?

The search controller was returning early when the search term was empty causing a bug where the dropdown toggles wouldn't show the correct text - instead defaulting to `Any`.

## Screenshots (if relevant)

![Screen_Shot_2016-09-09_at_12.09.57](/uploads/8c6bb36f4e163312314611d2877d5fa4/Screen_Shot_2016-09-09_at_12.09.57.png)

## What are the relevant issue numbers?

Closes #21783

See merge request !6277

Fix Cycle Analytics landing widget state and improve state management in Vue.

## What does this MR do?
- Fixes Cycle Analytics help widget show/hide issue
- Addresses initial MR feedback with improving Vue state management logic
- Fixes cookie path of the help widget so when you close a help widget in a repo it won't be visible for other repos.

## Are there points in the code the reviewer needs to double check?
- Should we move `gl.cycleAnalyticsModel` to a new file.

## Why was this MR needed?
- Addresses feedbacks of [initial MR](https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5986) and fixes #22483

## Screenshots (if relevant)

## 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)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [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)

## What are the relevant issue numbers?
Fixes #22483

See merge request !6492

Makes Cycle analytics mobile friendly

## What does this MR do?
Makes Cycle analytics page mobile friendly

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

## Why was this MR needed?
Cycle analytics page was not mobile friendly

## Screenshots (if relevant)
![optionB](/uploads/a1d7f2f4db100e1a8aa76c0156ef8641/optionB.png)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [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 [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [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)

## What are the relevant issue numbers?
fixes #22444

See merge request !6482

Fix a memory leak in HTML::Pipeline::SanitizationFilter::WHITELIST

See merge request !6456

Add link to broadcast messages docs

[ci skip]

See merge request !6495

Describe how the recent changes of CI permissions affect builds

## What does this MR do?

This describes how the CI permission changes

See merge request !6451

Revert the "accurate issuable counts in issuable list" feature

## Why was this MR needed?

!6455 introduced a performance killer, so we revert it until we find a proper solution that's not killing performance.

## What are the relevant issue numbers?

Revert !6455 and !4960.

See merge request !6476

fix dropdowns for mr-versions

## What does this MR do?
Change markup of mr version dropdowns to be in line with ui guidelines so that the dropdown content is scrollable.

## Why was this MR needed?
Dropdowns were not scrolling.

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [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
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] 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)

## What are the relevant issue numbers?
https://gitlab.com/gitlab-org/gitlab-ce/issues/21427

cc @brycepj @dzaporozhets

See merge request !6460

API: Return 404 when trying to fork to unaccessible namespace

Closes #22417

See merge request !6452

Fixes protected branches not removing active item

## What does this MR do?

Fixes an problem where protected branches weren't getting their active item removed on a second click because they dont have a field value.

## Why was this MR needed?

Protected branches could not have their clicked items removed once clicked.

See merge request !6440

Intercept issues search form submit to preserve filters.

## What does this MR do?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/896 by intercepting manual search form submission and redirecting it to use existing logic (now factored out into `executeSearch`).  

## Why was this MR needed?

Manual form submission (keying in 'enter') in issues search did not preserve applied filters. 

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/896

See merge request !6054

Fix pipeline error when trying to read empty merge request diff

When a user pushed something which resulted an empty merge request diff, `st_commits` would be `nil`. Therefore we also need to check if there exists `st_commits`.

We could tell this from:

``` ruby
def commits
  @commits ||= load_commits(st_commits || [])
end
```

and

``` ruby
def save_commits
  new_attributes = {}

  commits = compare.commits

  if commits.present?
    commits = Commit.decorate(commits, merge_request.source_project).reverse
    new_attributes[:st_commits] = dump_commits(commits)
  end

  update_columns_serialized(new_attributes)
end
```

Closes #22438

See merge request !6470

Hotfix the issuable counters when filtering by multiple labels

This is an ugly fix, but it make the counters work when multiple labels are selected so I think we should include it in 8.12, and try to find a proper fix afterward.

Closes #22421

See merge request !6455

Update merge request versions documentation with new screenshots

For #13570 based on https://gitlab.com/gitlab-org/gitlab-ce/issues/21427

See merge request !6454

Fixups for Frontend for Merge Request Diff

## What does this MR do?

Makes a few revisions to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6343, as per feedback from @DouweM. Specifically, it removes a duplicate in the changelog, removes colons in dropdowns, uses icon helper, and fixes the 'Show original' link path.

## Why was this MR needed?

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6343 was already merged and this is a needed patch. 

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6343

See merge request !6448

Update db/schema.rb per most recent migrations



See merge request !6446

Bump gitlab-shell upgrade version to 3.6.0 for 8.12

[ci skip]

Closes #22442

See merge request !6469

Fix typos in cycle analytics docs



See merge request !6467

Change location and refactor issue closing pattern documentation

## Moving docs to a new location?

See the guidelines: http://docs.gitlab.com/ce/development/doc_styleguide.html#changing-document-location

- [x] Make sure the old link is not removed and has its contents replaced with a link to the new location.
- [x] Make sure internal links pointing to the document in question are not broken.
- [x] Search and replace any links referring to old docs in GitLab Rails app, specifically under the `app/views/` directory.
- [x] If working on CE, submit an MR to EE with the changes as well.

See merge request !6466

Reorganize sections in Admin area settings

## What does this MR do?

Some settings were under the "wrong" category. This is an attempt to provide proper categories and move relevant settings there.

## What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/20126


See merge request !5449

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

This reverts merge request !6429

Fix Import/Export security specs

Related https://dev.gitlab.org/gitlab/gitlabhq/merge_requests/1987#note_83855

See merge request !1997