Update omniauth-saml to 1.6.0 to address a security vulnerability in ruby-saml

## What does this MR do?

Updates `omniauth-saml` to bring in the new `ruby-saml` dependency that addresses [CVE-2016-5697](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-5697)

Fixes #19206 

See merge request !4951

Correctly return todo ID after creating todo

See merge request !4941

Remove duplicate new page btn from edit wiki

## What does this MR do?
Removes duplicate button on wiki page

## What are the relevant issue numbers?
Closes #19075 

## Screenshots (if relevant)
![Screen_Shot_2016-06-24_at_9.45.28_AM](/uploads/8dca96c3e75b428d63acaaba6dede9a6/Screen_Shot_2016-06-24_at_9.45.28_AM.png)
![Screen_Shot_2016-06-24_at_9.45.57_AM](/uploads/e6ea97b07e48d2fe6f108d8c5a943583/Screen_Shot_2016-06-24_at_9.45.57_AM.png)

See merge request !4904

Mention gmake

Fixes https://gitlab.com/gitlab-org/gitlab-workhorse/issues/46

See merge request !4945

Fix check for existence of New Branch button on Issue page

## What does this MR do?

The condition in [`initCanCreateBranch`][initCanCreateBranch] mistakenly checks `$container` (the New Branch button) for falsy. However JQuery returns an empty array if no matching element was found, so this condition is never met.

## Why was this MR needed?

The wrong condition causes:
* `$.getJSON($container.data('path'))` to be called where `$container.data('path')` is `undefined`
* in this case `$.getJSON` uses `location.href`
* if the current page has a JSON representation, it is fetched and cached by browser and displayed the next time the page is visited (#17365)
* otherwise "Failed to check if new branch can be created" is displayed (#17264)

## What are the relevant issue numbers?

Fixes #17264 and #17365.

[initCanCreateBranch]: https://gitlab.com/gitlab-org/gitlab-ce/blob/v8.8.4/app/assets/javascripts/issue.js.coffee#L102


See merge request !4630

Revert Subresource Integrity pending a fix for Firefox's incorrect hashing implementation.

Per the discussion in #18230, Firefox support is broken :(

cc: @jschatz1 

See merge request !4943

Better debugging for memory killer middleware

This adds more info to the warning messages output by `MemoryKiller`.

Previously only the PID was showed, making it difficult to debug issues like https://gitlab.com/gitlab-org/gitlab-ce/issues/19124

This adds the worker class and job ID to the log messages.

See merge request !4936

Image sizing

## What does this MR do?

Limits image height to fit the screen. The wrapping div is so the image is guaranteed to be a block element without the link area growing to be larger than the image itself.

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

Make sure this can't be done in a more performant or concise way with Banzai.

## Why was this MR needed?

Images were displayed at their full resolution, which made it difficult to read issues when the image height was greater than the viewport height (see #18861).

## What are the relevant issue numbers?

Fixes #18861.

## Screenshots (if relevant)

Before:

![Screen_Shot_2016-06-20_at_3.25.26_PM](/uploads/158424375ade95adcd337ccd34c48747/Screen_Shot_2016-06-20_at_3.25.26_PM.png)

After:

![Screen_Shot_2016-06-20_at_3.24.57_PM](/uploads/f1a3b5f6442e4e3b1067332a547fb1c8/Screen_Shot_2016-06-20_at_3.24.57_PM.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] 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)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

cc: @jschatz1 @dzaporozhets @rspeicher

See merge request !4810

Test templates and GitLabCI parser againts each other

## What does this MR do?

Test the available templates against the preprocessor and vice versa

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

The dynamic creation of tests seems a little hacked. Is there a cleaner way?

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added -- Seems unneeded
- [x] 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)

See merge request !4898

Add max-height to prevent images from displaying larger than the provided screen size.

Also fix a failing test and add a new one.

Remove duplicate changelog entry

## What does this MR do?

Removes a changelog entry from 8.9.1, which is only present in 8.10



See merge request !4937

Allow "ci skip" to be in any case

## What does this MR do?

This MR makes the check for the [ci skip] tag in a commit message case insensitive and adds support for [skip ci].

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

No.

## Why was this MR needed?

I couldn't understand why some of my commits were being built, even though they contained "[CI Skip]".

## What are the relevant issue numbers?
N/A
## Screenshots (if relevant)
N/A
## 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] 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)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4785

Update EE downgrade instructions to include JenkinsDeprecatedService

EE now includes JenkinsDeprecatedService in addition to JenkinsService, so we need to clean both when downgrading from EE to CE.

Closes #19133
    
[ci skip]

See merge request !4916

Remove docs for GitLab CI Service API

## What does this MR do?

Documentation update: http://docs.gitlab.com/ce/api/services.html

Old GitLab CI Service API description will be removed from the docs.

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

n/a

## Why was this MR needed?

Obsolete information is harmful than nothing.

## What are the relevant issue numbers?

Closes #19167

## Does this MR meet the acceptance criteria?

- [n/a] [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)
- [n/a] 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)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4927

Add notices about disabling auth features for users with 2FA.

Related to #2979

- Document the proposed changes to the GitLab authentication system.
- This is done because currently, users with 2FA enabled are allowed API access without a 2FA token.

# Tasks

- [ ]  #2979 !xxxx - Document proposed auth changes for 2FA users
    - [x]  Wait for replies on "[potential avenues for documenting the planned changes](https://gitlab.com/gitlab-org/gitlab-ce/issues/2979#note_12591578)"
    - [x]  Update documentation
    - [ ]  CHANGELOG entry?
    - [ ]  Merge conflicts

See merge request !4815

Improve validations and error handling in new CI config entries

## What does this MR do?

This MR improves validation in new CI config.

## Why was this MR needed?

With that it will be easier to handle errors during validation and post-processing.

## What are the relevant issue numbers?

This is a continuation of #15060

See merge request !4560

Clean up some unused templates imported from GitLab CI

## What does this MR do?

Clean up some unused templates imported from GitLab CI, for new developers to easily understand the file/directory structure of Gitlab CE.

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

Be sure if removed files are not used now while the committer checked them once.

## Why was this MR needed?

Because the file/directory structure of the repository should be clear and simple and if so new developers can easily understand the file/directory structure of Gitlab CE.

## What are the relevant issue numbers?

Closes #19158 

## Does this MR meet the acceptance criteria?

- CHANGELOG won't be updated due to repository maintenance
- No documentation created/updated
- No API support added
- Tests
  - [skipped] 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)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4922

Add debugging tips with gdb



See merge request !4522

Removed unneeded word

Pretty simple, improved the wording a bit.

See merge request !4920

[ci skip]

Validate presence of essential params for diff rendering

## What does this MR do?

Check the presence of essential params before rendering diff content.
## Are there points in the code the reviewer needs to double check?

No
## Why was this MR needed?

To avoid the generated application error
## What are the relevant issue numbers?

#19096

## 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
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [ ] 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 !4917