Add linting for duplicate CHANGELOG entries

## What does this MR do?

Extend `scripts/lint-doc.sh` so that it checks that there are no duplicate versions in CHANGELOG.

See merge request !6039

Fixed large comments messing with diff table widths

## What does this MR do?

Fixes the width of the diff table so that the content inside it can't increase or decrease the width of the table cells.

## Screenshots (if relevant)

![Screen_Shot_2016-09-12_at_14.44.44](/uploads/2ca483399d867153e6ae608360ffea5f/Screen_Shot_2016-09-12_at_14.44.44.png)

## What are the relevant issue numbers?

Closes #20694

See merge request !6309

Improve build trace scroll controls

## What does this MR do?

The trace step buttons now correctly scroll to the top or bottom of the build trace, rather than jumping inconsistently and never full reaching the top due to the fixed position of the header/navigation area.

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

## Why was this MR needed?

Build trace UX

## Screenshots (if relevant)

![2016-09-09_20.04.32](/uploads/efee5145fb505f8c9ae2a4cf24d842d3/2016-09-09_20.04.32.gif)

## 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?

Contributes to #21832.

See merge request !6288

Fixes labels multi-encode and selecting labels with single quotes

## What does this MR do?

Replaced single quotes with escaped single quotes when setting item `.is-active` and when removing its field.

Adds a test to test selecting 2 different labels _(one with a single quote)_ with a full page load inbetween, it checks the labels are selected as well as shown as `.is-active` in the list.

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



## Why was this MR needed?

The javascript handles the url encoding when it is sent to the server so we shouldn't let the javascript begin processing an already encoded string but we needed to stop single quotes from breaking a jquery selector.

## Screenshots (if relevant)

https://youtu.be/-H0_L2hV9tM

## 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 #21961

Closes #21880

Closes #21248

Closes #20759

Closes #21935

See merge request !6313

# Conflicts:
#   app/assets/javascripts/gl_dropdown.js

Allow to set request_access_enabled for groups and projects using API

Closes #20978

See merge request !6359

Only create a protected branch upon a push to a new branch if a rule for that branch doesn't exist

A customer ran into an issue where a Sidekiq task retried over and over, leading to duplicate master branches in their protected branch list.
    
Closes #22177

See merge request !6399

Restrict last_activity_at updates to one per hour

This MR reduces the number of updates to `projects.last_activity_at` to once per hour.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/22213

See merge request !6391

Add Core Infrastructure Initiative badge to README

Our Core Infrastructure Initiative Badge page: https://bestpractices.coreinfrastructure.org/projects/42

CII is a program by the Linux Foundation to track compliance with best practices in various large open source projects, we currently have a 100% passing rate for the badge.

We didn't list this before, even though we probably should. I asked Sid and he said there was no reason not to add it, so here we go :)

See merge request !6077

The lock in turn is only obtained when actually needed, reducing some
load on Redis.

Fixes gitlab-org/gitlab-ce#22213

Make CI to use the permission of the user who is trigger the build

This is continuation of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5735, but with removed all LFS code that is added by: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6043.

This also incorporates most of LFS code added in !6043 to simplify further merge.

See merge request !6409

Fix import/export database errors

Fixes protected branches errors when importing a project including them

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/21295

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/21799

See merge request !6099

Add support for dynamic environments

Implements proposal described in https://gitlab.com/gitlab-org/gitlab-ce/issues/21971.

Specifically:
- it adds a `.gitlab-ci.yml` configuration,
- it allows environment name to have slashes,
- it allows environment names to use CI predefined variables,
- it allows to specify URL from `.gitlab-ci.yml`,
- it allows the URL to use CI predefined variables,
- it introduces `environment_type` to allow to easily group environments in the future

See merge request !6323

Ensure validation messages are shown within the milestone form

Fixes a bug where upon entering data to create an invalid milestone via the Web UI or the API would raise an exception rather than render the validation messages

We'd rather render the validation messages to inform the user than raise an exception and result in a 422 error being displayed

Closes #22033

See merge request !6345

Reset pushes_since_gc counter before specs run to ensure starting point is 0

See merge request !6406

Render invalid template for open merge requests without source project

If source project was removed and merge request for some reason wasn't closed is rendered `invalid` template. Fix !6177

Fix #22248 

See merge request !6383

Add missing spec for ProtectedBranches::CreateService

While working on !6399, I noticed there was no spec for this class so I added one.

See merge request !6405

* Remove call to Milestone#save! instead just Milestone#save
* Add safety specs to stop a regression

Fixes #22033

Refactor boards_spec.rb to avoid code duplication

Originally created to address #21197, but !6224 solved the intermittent spec failures.

See merge request !6197

Squashed commits:
[f9a9315] Use : to test invalid environment name