Fix duplicate master entries in the mr versions dropdown

## What does this MR do?

Fixes bug when "master" was duplicated per each mr version in the dropdown

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/22519, Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/22715

See merge request !6567

Reduce duplication in `Gitlab::Diff::PositionTracer`

## What does this MR do?

This factorize similar code from `Gitlab::Diff::PositionTracer`

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

The code might be harder to understand now...

## Why was this MR needed?

To get rid of flay offense.

## Does this MR meet the acceptance criteria?

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

## What are the relevant issue numbers?

Closes #22202

See merge request !6365

AbstractReferenceFilter caches current project_ref on RequestStore when active

See merge request !6545

Before we weren’t caching current_project_ref because normally the reference to 
the current project doesn’t include the path with namespace. But now we store 
the current project in the projects reference cache to be used for the same 
filter when accessing using path with namespace of for subsequent filters executed on the cache.

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Add university content

## What does this MR do?

Imports gitlab-org/University content into doc/university to deprecate university.gitlab.com and access it from doc.gitlab.com/universtiy.

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

That there are no broken links.

## Does this MR meet the acceptance criteria?

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

## What are the relevant issue numbers?

#22449

See merge request !6520

"Banzai::ReferenceParser::BaseParser is executing queries that don't return results"

See merge request !6546

Add footnote to Markdown docs

_Originally opened at !3741 by @bbodenmiller._

- - -

See merge request !6564

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

Reduce output to the build log

Remove a log of useless info from the build log by adding `--quiet` flag. [Bundler docs](https://bundler.io/v1.2/bundle_install.html)

See merge request !6560

Added git http requests tests for user with LDAP identity

## What does this MR do?

Added tests to git http request for a user with ldap identity.

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

In order to stick to the way the existing tests are defined in spec files, I have added the new tests in the same spec file that coveres the git http request feature and thus it seems to be a lot of changes in the git_http_spec.rb when looking at the commit git in Gitlab, but the largest change is indentation so please check with a better diff tool (i.e. kdiff3).

Let me know if this is OK with you or do you want to have a new file introduced (i.e. `git_http_ldap_spec.rb`)

## Why was this MR needed?

To increase test coverage and to make sure  the changes that will be introduced by #20820 will not introduce any regressions.

## What are the relevant issue numbers?

#20820

See merge request !6559

Log LDAP lookup errors and don't swallow unrelated exceptions

- Previously all exceptions were ignored, now only `Net::LDAP::Error` and exceptions that inherit from it are caught by the `rescue` clause. There might be other exceptions that should also be ignored / dealt with.
- Not sure if the Rails production log is a good choice for this, or if the GitLab application log would be more appropriate.

See merge request !6558

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

Bump ruby prof to 0.16

See merge request !6557

Signed-off-by: Roger Meier <r.meier@siemens.com>

This solve issues with ruby builds with rubygems preload
see https://github.com/ruby-prof/ruby-prof/pull/191Signed-off-by: Rémy Coutable <remy@rymai.me>

Changed to v-cloak attr to hash rocket and string 'true'

## What does this MR do?

Changed to v-cloak attr to hash rocket and string 'true'

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

## Why was this MR needed?

Maybe it's killing `master`? 😕 

## 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?

See merge request !6553

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

Optimize GitHub importer for speed and memory

See merge request !6552

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

Fix IssuesController#show degradation including project on loaded notes

See merge request !6540

* No need to re-fetch issues from GH to read their labels, the labels
  are already there from the index request.
* No need to look up labels on the database for every application, so we
  cache them.

This should avoid having large memory growth when importing GitHub repos
with lots of resources.

Add more tests for calendar contribution

## What does this MR do?
Add more tests for calendar contribution

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

## Why was this MR needed?
Improve test coverage for calendar

## Screenshots (if relevant)
None

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry 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 #22347

See merge request !6421

Use gitlab-shell v3.6.2

## What does this MR do?

Bump gitlab-shell to v3.6.2 to be able to enable GIT_TRACE_PERFORMANCE output to a log file

Relates #22053

See merge request !6367