Bump gitlab_git to 10.2.3 to fix false truncated warnings with ISO-8559 files

Closes #18690


See merge request !4884

Added basic docs for the Emoji Rake tasks

## What does this MR do?

This MR adds basic documentation for the two Emoji Rake tasks.

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

Spelling, that sort of thing.

## Why was this MR needed?

These Rake tasks only had some small amount of source level documentation.

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/14794

## 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)
- [ ] 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 !4877

Fix user creation with stronger minimum password requirements

## What does this MR do?

`doc/security/password_length_limits.md` Describes a way to increase minimum requirements of passwords, via `config/initializers/devise_password_length.rb`. However, user creation hardcoded password generation at 8 characters.

If the minimum was set at any more than 8 characters, user creation will fail.

Function now looks up minimum length requirement.

## What are the relevant issue numbers?

Fixes #14563.

## 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)
- 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 !4054

Closes #18690

Fix merge requests project settings help link anchor.

## What does this MR do?

8.9.0 added a new project option for merge requests which has a link for help.   The link contained an anchor which was being encoded as ```%23``` so change the help link to properly configure the anchor.

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

None

## Why was this MR needed?

Current release causes 404 error when clicking on the help link in project settings.

## What are the relevant issue numbers?

Closes #18982 

## 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
  - [ ] Added for this feature/bug
  - [ ] 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 !4873

Use memorized tags array when searching tags by name

See merge request !4859

Fix 404 for pipelines

## What does this MR do?
Allow to access pipelines of public project by logged guest.

## What are the relevant issue numbers?
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/17885

## 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 !4881

Fix pagination on sorts with lots of ties

## What does this MR do?

Fixes #18915. As we only order by the sorted column, we don't have any tie-breaker. Some orderings, like priority and weight, have lots of ties, so you can see duplicate results as you page through. (Timestamp columns are less susceptible to this.)

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

I just picked `id DESC`, this could as easily be `id ASC`.

## Why was this MR needed?

Postgres and MySQL don't guarantee that pagination with `LIMIT` and
`OFFSET` will work as expected if the ordering isn't unique. From the Postgres docs:

> When using `LIMIT`, it is important to use an `ORDER BY` clause that
> constrains the result rows into a unique order. Otherwise you will get
> an unpredictable subset of the query's rows

Before:

    [1] pry(main)> issues = 1.upto(Issue.count).map { |i| Issue.sort('priority').page(i).per(1).map(&:id) }.flatten
    [2] pry(main)> issues.count
    => 81
    [3] pry(main)> issues.uniq.count
    => 42

After:

    [1] pry(main)> issues = 1.upto(Issue.count).map { |i| Issue.sort('priority').page(i).per(1).map(&:id) }.flatten
    [2] pry(main)> issues.count
    => 81
    [3] pry(main)> issues.uniq.count
    => 81

See merge request !4878

Fix clickable code search results

Closes #17860

See merge request !4654

Postgres and MySQL don't guarantee that pagination with `LIMIT` and
`OFFSET` will work if the ordering isn't unique. From the Postgres docs:

> When using `LIMIT`, it is important to use an `ORDER BY` clause that
> constrains the result rows into a unique order. Otherwise you will get
> an unpredictable subset of the query's rows

Before:

    [1] pry(main)> issues = 1.upto(Issue.count).map { |i| Issue.sort('priority').page(i).per(1).map(&:id) }.flatten
    [2] pry(main)> issues.count
    => 81
    [3] pry(main)> issues.uniq.count
    => 42

After:

    [1] pry(main)> issues = 1.upto(Issue.count).map { |i| Issue.sort('priority').page(i).per(1).map(&:id) }.flatten
    [2] pry(main)> issues.count
    => 81
    [3] pry(main)> issues.uniq.count
    => 81

Remove Rubocop skip comment from migration style guide

This was an error in previous MR https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4693

[ci skip]

See merge request !4879

Fixes gitlab-org/gitlab-ce#14794 gitlab-com/performance#13

[ci skip]

Fix errors found on importing GitLab CE repo

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18968

See merge request !4855

Use influxdb-management for managing InfluxDB

## What does this MR do?

This updates the InfluxDB documentation so it suggests using https://gitlab.com/gitlab-org/influxdb-management instead of requiring users to manually copy-paste queries into an InfluxDB shell.

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

Mostly spelling and if the writing style makes sense.

## Why was this MR needed?

The same list of queries was duplicated in multiple places and it was hard to manually keep this up to date.

## Does this MR meet the acceptance criteria?

- [x] ~~[CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added~~ Not really tied into a version
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] 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 !4875

Add Sidekiq job latency to transaction metrics.

See merge request !4871

This removes the need for manually updating the list of queries every
time we make a change.

[ci skip]

Updated InfluxDB continuous queries for 8.9.0

See merge request !4872

[ci skip]

Added bottom padding to label color suggestion link

## What does this MR do?

Adds a bottom margin to label color suggestions to make sure that when wrapped there is enough whitespace between color rows.

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

😕 

## Why was this MR needed?

Mobile UX.

## What are the relevant issue numbers?

Closes #18857.

## Screenshots (if relevant)

![Screen_Shot_2016-06-22_at_00.31.26](/uploads/f49c7fa2b97b13e69f0dea97c5dfb319/Screen_Shot_2016-06-22_at_00.31.26.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 [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 !4845

Restrict header logo to 36px so it doesn't overflow.

## What does this MR do?

Fixes the logo in the header.

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

I don't think so.

## Why was this MR needed?

Logos that weren't 36px by 36px were broken in 8.9.0

## What are the relevant issue numbers?

Fixes #18980

## Screenshots (if relevant)

Before:

![Screen_Shot_2016-06-22_at_1.52.54_PM](/uploads/de6e4d9ccf40b972565e3864173a9907/Screen_Shot_2016-06-22_at_1.52.54_PM.png)

After:

![Screen_Shot_2016-06-22_at_1.52.37_PM](/uploads/d72e015263888b5155c1db5e25f54d66/Screen_Shot_2016-06-22_at_1.52.37_PM.png)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [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 !4861

Add caching for Ruby 2.3 tests.

Accidentally removed when !3807 was merged.

See merge request !4868