Use `default_value_for` to handle null values in only_allow_merge_if_all_discussions_are_resolved

Small style improvement for !7427

See merge request !7460

[ci skip]

Issue #13823: random message when all Todos are Done

## What does this MR do?

Shows a random message every time the To Do list is empty: https://gitlab.com/gitlab-org/gitlab-ce/issues/13823

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

It's my first contribution to GitLab so I might need some help:

 - I'm loading a yaml file in the controller. I'm not sure where would be the best place to put it.
 - I'm also having the error below running the tests but it doesn't seem related to my changes. I think I might have some issue with my config. Could you double check if the tests pass for you?

/home/pep/.rvm/gems/ruby-2.3.1/gems/actionpack-4.2.7.1/lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call': No route matches [GET] "/autocomplete/users/sjobs@apple.com.json" (ActionController::RoutingError)

## Why was this MR needed?

https://gitlab.com/gitlab-org/gitlab-ce/issues/13823

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [x] [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
  - [x] 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)
- [x] Branch has no merge conflicts with `master` (if it does - 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?

https://gitlab.com/gitlab-org/gitlab-ce/issues/13823

See merge request !6818

21778 Correct css styles for pinned navigation

## What does this MR do?
Fixes css for header and comment notes when sidebar is pinned

## Screenshots (if relevant)
Before:
![Screen_Shot_2016-11-08_at_11.02.55_AM](/uploads/ae7bb1f477b2ffbd4d4e0364f2770816/Screen_Shot_2016-11-08_at_11.02.55_AM.png)
After:
![Screen_Shot_2016-11-08_at_11.02.34_AM](/uploads/cf0b9f9f175aa5c6c7e79640b76b1040/Screen_Shot_2016-11-08_at_11.02.34_AM.png)

Before:
![Screen_Shot_2016-11-08_at_11.03.21_AM](/uploads/f48ea742ee6dbb86874e47dd27eddadd/Screen_Shot_2016-11-08_at_11.03.21_AM.png)
After:
![Screen_Shot_2016-11-08_at_11.02.19_AM](/uploads/312b27ba07e04ceb96f8ed9d6f167bee/Screen_Shot_2016-11-08_at_11.02.19_AM.png)
## Does this MR meet the acceptance criteria?

- [ ] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) 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 it does - 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 #21778 

cc @mikegreiling

See merge request !7362

Give search-input correct padding-right value

## What does this MR do?
This fixes how `padding-right: 20px` was being applied to the style rule of `.search-input`, preventing text in that form from clipping through `.search-icon`

## Are there points in the code the reviewer needs to double check?
If there are any cases where `.search .search-input` is used in a search form where there is no right-side icon (I could not find such occurrence myself).

## Why was this MR needed?
Some text in long search queries were being hidden by the close icon being used in the search form. This makes it a bit more presentable. ;)

## Screenshots (if relevant)
__Before__
![before](/uploads/2757a6264a1d2053af7212f72df7c3f9/before.png)

__After__
![after](/uploads/322fbfa08594f0f33d10a3226c82326d/after.png)

See merge request !7407

Use declared_params helper in API

Related to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7406#note_18275781

See merge request !7455

Fixed issue boards when not logged in

## What does this MR do?

This managed to get through because their wasn't actually any tests for loading the lists when a user is not logged in. This fixes that by adding a test & also fixing the template not correctly compiling under VueJS v2.

See merge request !7452

Project download buttons always show

## What does this MR do?
Removes `hidden-xs hidden-sm` classes from `download-button` so it doesn’t hide itself individually from the rest of the `project-repo-buttons` block

## Why was this MR needed?
Fixes #23960. Not sure why this element had these classes in the first place, but at the very least we shouldn’t be hiding the Download button at the `hidden-sm` threshold since that’s still fairly large viewport and users with viewports of that size likely still want to download source code.

## Screenshots (if relevant)
Screenshots taken at ~830px width
__Before__
![before](/uploads/21955cf7a12f6eb9cfef96bbb27b7110/before.png)

__After__
![after](/uploads/c082884f225184d56a920adbc0a0a732/after.png)

## What are the relevant issue numbers?
#23960

See merge request !7405

Use to_h to convert params to a hash

See merge request !7406

Fix typos and grammar errors

See the general Documentation guidelines http://docs.gitlab.com/ce/development/doc_styleguide.html

See merge request !7451

Improve naming convention in ci configuration module

## What does this MR do?

This MR improves the naming convention in CI configuration module to reflect the domain design better.

## What are the relevant issue numbers?

Related to #15060

See merge request !7448

Grapify subscription API

## What are the relevant issue numbers?

Related to #22928

See merge request !7380

Fix error links in help index page when access it with url `http://gitlab.example.com/help/` which have an extra slash 

Fixes #24349

See merge request !7396

Only turn on Sidekiq throttling if column exists

If the database has not been migrated properly, the initializer for Sidekiq will fail to start and cause the whole Rails server to crash. This change checks the existence for the column and allows Rails to start even if the setting has not been added as a database column.

Closes #24452

See merge request !7446

[ci skip]

Centralized all LDAP config logic in to `Gitlab::LDAP::Config`. We had varying configuration for devise/omniauth and other things. For example, `user_filter` was never taken in to account for devise/omniauth so a user object would always be created, even if the user did not match the user_filter. 

Fixes gitlab-org/gitlab-ce#21195, https://gitlab.com/gitlab-org/gitlab-ce/issues/15396 and gitlab-org/gitlab-ce#13296

See merge request !6606

Remove unneeded nil checks

See merge request !7437

Fix project Visibility level selector not using default values

closes #20245

See merge request !7264

Added ability to put emojis into repository name

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

Ensure that regexp used is correct, I used the following list: http://www.unicode.org/Public/emoji/1.0/emoji-data.txt

See merge request !7420

use single quote for consistency

See merge request !7442

Resolve "Link from build page to its pipeline"

## What does this MR do?

Adds references and links to a build's pipeline within both individual build pages and the build index.

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

Nothing springs to mind

## Why was this MR needed?

See #22307

## Screenshots (if relevant)

![Screen_Shot_2016-10-24_at_3.45.39_PM_copy](/uploads/e6e8745a0a39d8b71c007e7df5fbd051/Screen_Shot_2016-10-24_at_3.45.39_PM_copy.png)

![Screen_Shot_2016-10-24_at_3.46.03_PM_copy](/uploads/3e2eb656347751f10bf62891b56ebcc7/Screen_Shot_2016-10-24_at_3.46.03_PM_copy.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry added
- Tests
  - [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 it does - 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?

Closes #22307

See merge request !7082

Only run builds on master of CE or EE

This should reduce builds run by projects still running all pipelines for CE

See merge request !6869

If the database has not been migrated properly, the initializer for Sidekiq
will fail to start and cause the whole Rails server to crash. This change
checks the existence for the column and allows Rails to start even
if the setting has not been added as a database column.

Closes #24452

Fix link to index.md UX guide in development README.md

Fix wrong link to UX docs that introduced by
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7142

See merge request !7444

[ci skip]

Improvements to hover/active/focus states in header items

## What does this MR do?

Adds some improvements to buttons, dropdowns, inputs, etc. in the header area.

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

I'm not sure.

## Why was this MR needed?

Requested in an issue.

## Screenshots (if relevant)

![caret](/uploads/574135282e4b2e81476fdd6dd6c1c05d/caret.gif)![hover](/uploads/15a3b8a2aa89baf20270be97c452e006/hover.gif)

## Does this MR meet the acceptance criteria?

- [ ] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) 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 it does - 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 #24202 


This is not complete yet. I'm new to this, so please let me know what all steps do I need to do (tests, changelog, etc.).

See merge request !7412

Fix record not found error on NewNoteWorker processing

Resolves #22678 

See merge request !6863