Add endpoints for pipelines

- [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] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] 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 !5837

Add merge conflict resolution to CHANGELOG

😊 

See merge request !5863

Fix email line-height in Outlook

On Outlook.com:

![image](/uploads/4bfa8daacce39a640428dff6eec0c098/image.png)

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/19060.

See merge request !5843

Fix broken feature spec.

This older spec was failing: features/project/issues/issues.feature

Looks like before we were doing an exact match for queries, that's why
it was passing with this existing issue: https://gitlab.com/gitlab-org/gitlab-ce/blob/59fa031e6f7d5a1b658c370f581c4caaf4493150/features/project/issues/issues.feature#L128

Failed build: https://gitlab.com/gitlab-org/gitlab-ce/builds/3178231

See merge request !5857

Remove undefined word Corporation from CCLA

## What does this MR do?

Removes the (undefined) word "Corporation" from the CCLA, per advice from legal counsel.

## Why was this MR needed?

The word Corporation was undefined, while the word "You" already included "legal entities".

## What are the relevant issue numbers?

- https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3685
- https://gitlab.com/gitlab-org/gitlab-ce/issues/15156

\cc @pmachle

See merge request !5835

Simplify SQL queries of marking a todo as done

See merge request !5832

Update changelog

## What does this MR do?
Updates Changelog: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5485#note_14008742

See merge request !5854

Follow-up on 52b0c26

Update gitlab_git gem to 10.4.7

See merge request !5851

Fix documentation of gitlab-ci's `when` keyword.

## What does this MR do?

Fixes description of the `when` keyword in the Jobs keywords description table.

## 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 [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 !5868

Make new tabs persistent when changing view.

## What does this MR do?

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

## Why was this MR needed?

## What are the relevant issue numbers?

## 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 [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)

cc @stanhu @DouweM @rdavila 

See merge request !5859

Refactor description templates documentation

## What are the relevant issue numbers?

Refactors docs introduced by https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4981

See merge request !5839

Test was not waiting for the page to be fully loaded

This older spec was failing: features/project/issues/issues.feature

Looks like before we were doing an exact match for queries, that's why
it was passing with this existing issue: https://gitlab.com/gitlab-org/gitlab-ce/blob/59fa031e6f7d5a1b658c370f581c4caaf4493150/features/project/issues/issues.feature#L128

Failed build: https://gitlab.com/gitlab-org/gitlab-ce/builds/3178231

Add pipeline graph

## What does this MR do?
Adds pipeline visualization

## What are the relevant issue numbers?
Closes #18141    
Part of #19982 

## Screenshots (if relevant)
![Screen_Shot_2016-08-16_at_7.59.52_PM](/uploads/c9dd695d2ddbd2a85e98a5b4e500d52c/Screen_Shot_2016-08-16_at_7.59.52_PM.png)
![Screen_Shot_2016-08-16_at_7.55.49_PM](/uploads/5ab548cc5fc8a42371d3b54108798c02/Screen_Shot_2016-08-16_at_7.55.49_PM.png)

See merge request !5742

Collapse build tabs that don't fit

## What does this MR do?
* Orders tests from `failed` > `pending` > `running` > `canceled` > `skipped` > `success`
* Put stages in one dropdown
* Once stage is selected, second dropdown shows all builds/jobs for that stage

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

## Why was this MR needed?
So many tests!   
<img src="/uploads/d581b2670588121c6d64823f61906a1a/Screen_Shot_2016-08-01_at_9.52.50_AM.png" width="600px">

## What are the relevant issue numbers?
Closes #18516    
Part of #19982

## Screenshots (if relevant)
![Screen_Shot_2016-08-17_at_1.14.20_PM](/uploads/fa183361ed13137257caf20a6afc4ef1/Screen_Shot_2016-08-17_at_1.14.20_PM.png)
![Screen_Shot_2016-08-17_at_1.14.39_PM](/uploads/f568cac463abf5c625cf31912ddbd00a/Screen_Shot_2016-08-17_at_1.14.39_PM.png)

See merge request !5595

Fix icon alignment of star and fork buttons

## What does this MR do?

Fix alignment of star and fork icons.

## Why was this MR needed?

Buttons had more padding on the left than on the right.

## What are the relevant issue numbers?

fixes #20001 

## Screenshots

<table>
<thead><th>Before</th><th>After</th></thead>
<tr>
  <td><img alt="fork-button-before" src="/uploads/664c0bc935f4c48899f5b63a1c215cbc/fork-button-before.png"></td>
  <td><img alt="fork-button-after" src="/uploads/9385427a5b178487bd24cd2f8ec4a5ed/fork.png"></td>
</tr>
<tr>
  <td><img alt="project-buttons-before" src="/uploads/48ef41458433b468afc2919eb24849cc/project-buttons-before.png"></td>
  <td><img alt="project-buttons-after" src="/uploads/3bafe6e68645d787a2cdb79cd164335f/project-actions.png"></td>
</tr>
</table>

See merge request !5451

Remove sleep calls introduced in !5740

See merge request !5815

Send notification emails when users are newly mentioned in issue or MR edits

## What does this MR do?

Introduces "new mention in issue" and "new mention in MR" email notifications.  Editing a Mentionable title or description and adding a mention to a user who was not previously mentioned will now send them a notification email, following usual permissions for doing so.

## Why was this MR needed?

Issues & MRs may be edited to include mentions to new people. We don't currently send out email notifications of these edits to anyone, although they do create TODOs. This brings email notifications into parity with TODOs.

## What are the relevant issue numbers?

Closes #2451

See merge request !5800

Hide "Create new list button" on Issues and MRs pages

![1](/uploads/d8b08cb62cfc9e9d29e3e64b2ed0a8af/1.png)

/cc @jschatz1 

See merge request !5852

Add delimiter to project stars and forks count

## What does this MR do?
Adds the `number_with_delimiter()`to the project stars and fork counts on the projects dashboard.

## Are there points in the code the reviewer needs to double check?
Shouldn't be any 😃  

## Why was this MR needed?
Improve readability and adhere to the [UI guide](https://gitlab.com/help/development/ui_guide.md#counts)

## What are the relevant issue numbers?
Closes #20746 

## Screenshots (if relevant)
Before:
![Screen_Shot_2016-08-09_at_1.30.44_PM](/uploads/69592ce220d64774e265cfbcfcb6864a/Screen_Shot_2016-08-09_at_1.30.44_PM.png)

After:
![Screen_Shot_2016-08-09_at_1.30.58_PM](/uploads/1470179256614c2e47cc9d0e49aeaf09/Screen_Shot_2016-08-09_at_1.30.58_PM.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- Tests
  - [x] 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 !5741

Fix merge request new view not changing code view rendering style

Correctly respects the code view changing when creating a merge request.

Closes #20808

See merge request !5768

Issue boards

## What are the relevant issue numbers?

- Issue: #17907 
- Issue backend: #20335 
- Backend MR: !5548
- Frontend MR: !5554
- Documentation !5713 

## Screenshots (if relevant)

## 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] ~~API support added~~
- Tests
  - [x] Added for this feature/bug
  - [x] 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)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5548