Teach GitLab not only to merge changes from a merge-request, but also to
apply patches posted to merge-request in a way like `git am` would do -
without merge commit and directly on top of current branch. Which way to
go is selected by user in web UI, and apply patches is the first option.

There are 3 cases:

- only 1 commit is present in MR -> the only available option is to
  apply that single commit as one patch without a merge

  ( There is no need for merge commit in this case at all: information
    about user who applied the patch goes to "Committer" field in resultant
    commit. Avoiding 1 merge per 1 patch results in cleaner history )

  It is also possible to review patch description directly in web UI,
  before doing the actual application, and correct / amend it as needed.

- several commits are present in MR:

  * it is possible to apply the patches directly on top of current
    branch. Again information about who applied what goes to "Committer"
    field.

  * it is possible to merge MR changes with making a merge commit.

    This variant is useful, when patches from a MR do several logical
    steps to reach one goal, and MR description contain cover letter for
    whole patch series.

    in this case original commits stay untouched and resulting merge
    will contain MR author as author, user who accepted MR as committer,
    and cover letter as merge commit message.

    NOTE we avoid useless "Merge branch X into Y" in merge message, and
        just put MR title into merge subject and MR description into merge
        description.

        This way it is more logical with more important information in
        merge subject and thus e.g. more handy to oversee what a merge brings,
        just by it subject, e.g. via looking at updates via

            gitk --first-parent ...

        or via web.

NOTE for pre-generated references to merge-request we now use full MR
    URL, instead of !<MR-n>. Full URLs work everywhere, not only on
    original site where MR was created, or even only in original repo
    and not its fork on the same site.

TODO detect whether request comes from China and only then show ICP (?).

We show in small font size the same info that is shown on sign_in page:

    "GitLab Nexedi Edition", "About GitLab" and "About Nexedi"

This is good to have and hereby-introduced about-footer area will be
also used in the next patch for ICP too.

XXX placement of .about-footer to be near bottom is done not very
correctly.

Like Omnibus, SlapOS version does not have init script - nothing to
check here.

This is handy for monitoring tools, which could e.g. periodically call check
tasks and instead of parsing output, rely on exit code.

The way we detect if something failed is via hooking into String#red, and if
anything was ever printed in red - that's an error.

The default was switched to HTTP in the previous patch, but let's completely
remove SSH option - we support only HTTP for git fetch/push.

Both fetch and push are possible over https, which is selected by http if
gitlab was configured to use https in external url.

This way to reduce security vectors and possible ways to interact with gitlab
we use https only without ssh at all.

= GitLab Community Edition + Nexedi patches

[ci skip]

Fix build dependencies, when the dependency is a string

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/14485

See merge request !3344

Fix sorting issues/mrs by votes on the groups page

Closes #14394

The `non_archived` scope applied here https://gitlab.com/gitlab-org/gitlab-ce/blob/master/app/controllers/concerns/issues_action.rb#L5 overrides the previous `ORDER BY` applied inside the IssuesFinder, with the default scope of the Project model, resulting in SQL errors.

```ruby
Issue.reorder(created_at: :desc).joins(:project).to_sql
=> "SELECT issues.*
    FROM issues INNER JOIN projects ON projects.id = issues.project_id
    ORDER BY issues.created_at DESC"

Issue.reorder(created_at: :desc).joins(:project).merge(Project.non_archived).to_sql
=> "SELECT issues.*
    FROM issues INNER JOIN projects ON projects.id = issues.project_id
    WHERE projects.archived = 'f'
    ORDER BY projects.id DESC"

Issue.reorder(created_at: :desc).joins(:project).merge(Project.non_archived.only(:where)).to_sql
=> "SELECT issues.*
    FROM issues INNER JOIN projects ON projects.id = issues.project_id
    WHERE projects.archived = 'f'
    ORDER BY issues.created_at DESC"
```

/cc @yorickpeterse

See merge request !3333

Fix an issue causing the Dashboard/Milestones page to be blank

Fixes #14505 and #14514.

See merge request !3348

Fixed bug where participants would not work correctly on merge requests

Also fixed alignment bug with can't merge badge

Closes #14478, #14494

See merge request !3329

Display nav controls on mobile

Set inputs inside .nav-controls to full-width on viewports below 600px

Fixes #13885

**Affected pages**

/dashboard/groups

/admin/builds

/dashboard/projects

/dashboard/issues

/dashboard/merge_requests

/dashboard/milestones

/dashboard/todos

/explore

/groups/{group-name}/issues

/groups/{group-name}

/groups/{group-name}/milestones

/{group-name}/{project-name}/builds

/{group-name}/{project-name}/forks

/{group-name}/{project-name}/issues

/{group-name}/{project-name}/labels

/{group-name}/{project-name}/merge_requests

/{group-name}/{project-name}/milestones

/{group-name}/{project-name}/wikis/home

/{group-name}/{project-name}/wikis/pages

Some Screenshots

**Groups**

![Screen_Shot_2016-03-15_at_2.22.23_PM](/uploads/b55348676693cc3ff67cddc4528f7f6c/Screen_Shot_2016-03-15_at_2.22.23_PM.png)

**Admin > Builds**

![admin-builds](/uploads/2e84119660f4895a1530883412c4b728/admin-builds.png)

**TODOs**

![todos](/uploads/84344c43011e22f902701038932d3eaa/todos.png)

**Dashboard > Projects**

![dashboards-projects](/uploads/f508d9107598038798aa10485d3d5cfe/dashboards-projects.png)

**Project Issues**

![issues](/uploads/d6c69a8f81ee07da95b2a3b99b81cf51/issues.png)

**Project Merge Requests**

![merge_requests](/uploads/b3c1a537f28931bd38077c36627a0d7a/merge_requests.png)

See merge request !3214

Fixes issue with assign milestone not loading milestone list

cc. @jschatz1

See merge request !3346

Shows error messages when trying to create label in dropdown menu

Closes #14495

![Screen_Shot_2016-03-22_at_14.46.10](/uploads/cdcaa51f4d41237f8027efbd0f894bcd/Screen_Shot_2016-03-22_at_14.46.10.png)

See merge request !3345

User has to confirm deletion of issuables

Closes #14474

See merge request !3341

Moving of issuables only when the record already exists

Closes #14489

See merge request !3340

Auto collapses the navigation when resizing

Closes #14475

![auto-collapse](/uploads/332c6261acb6bc30d7d30cbdfafe92eb/auto-collapse.gif)

See merge request !3343

Fixes issue with signin button overflowing on mobile

Closes #14477

![Screen_Shot_2016-03-22_at_13.52.51](/uploads/7c9b2c38be7d497c690a7d17ae0ca76d/Screen_Shot_2016-03-22_at_13.52.51.png)

![Screen_Shot_2016-03-22_at_13.52.43](/uploads/8b2432aeb4afec455286fced11c5490c/Screen_Shot_2016-03-22_at_13.52.43.png)

See merge request !3342

Restrict notifications for confidential issues

Closes #14468

/cc @rymai

See merge request !3334

Reload the schema before restoring a database backup

If a user tries to downgrade and restore after a failed upgrade,
the database may still contain newer tables. Reload the older
schema before restoring the database to avoid future upgrade
problems. Also, add a rake task to help users add migration
versions to the database so it's easier to recover from these
errors if they do occur. Fixes #13419

See merge request !2807

[ci skip]

Add docs on group visibility

Accompanying https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3323

See merge request !3338

GitLab intro docs

Related to https://gitlab.com/gitlab-org/marketing_monthly_release/issues/1

---

Need refactor:

- Create a new project
- Create a new group
- Create a new issue
- Assign labels to issues
- Use milestones as an overview of your project's tracker
- Fork a project and contribute to it
- Create a new merge request
- Automatically close issues from merge requests (include GitLab.com pattern)
- GitLab CI quick start guide (make it easier to follow)

Moved to https://gitlab.com/gitlab-org/gitlab-ce/issues/8068

See merge request !3225

Soft delete issuables

Fixes #2489 

What still needs to happen: research on the indexes, the gem suggests a [lot of changes](https://github.com/rubysherpas/paranoia#about-indexes) though this is probably a good idea to discuss and I'm unsure on the impact of an omnibus upgrade as I suspect creating about 10 new indexes has a large impact on the downtime.

TODO: 
- [x] Also group owners can ***soft*** delete
- [x] Button should be hidden

See merge request !2982

Prevent tokens in the import URL to be showed by the UI

Quick fix to prevent the import URL to show a user's token.

See merge request !3331

CI: Add 'triggers' keyword to 'only' and 'except' lists to allow control over when triggers cause builds to run

Currently, the `only` and `except` keywords in `.gitlab-ci.yml` only accept ref names or the special `branches` and `tags` keywords. However, these are primarily useful when controlling how repository activity affects the creation of builds. In my case, instead of building on every commit, I'd like to use the following logic:

- If the repository is tagged, do a build.
- Any other normal commits should not cause a build.
- If a build is triggered via the API, always create one for the specified ref.

From what I can tell, this isn't possible via the existing YAML syntax. In this MR, I introduce a new keyword `triggers` that goes along with `branches` and `tags`. I can implement the logic above using the following job configuration:

```yaml
only:
  - tags
  - triggers
```

I updated the tests and documentation to reflect this and everything seems to pass.

See merge request !3230

Fix Indentation lints in CSS.

As discussed in #14299.

cc: @jschatz1 

See merge request !3312

Remove duplicated ago

Closes #14460 

See merge request !3332

Changing project icon

Closes #14196

See merge request !3268

Follow the CSS Style Guide rules for using shorthand where possible.

Fixes violations of the Shorthand rule. All of these were done manually and I reviewed each change to verify, so they should all be right.

Discussed in #14299.

cc: @jschatz1 

See merge request !3313

Check if index exists before adding it

I got an error when updating GDK because it already exists.

[ci skip]

See merge request !3335

Add group visibility level

Supersedes https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3051

Closes #12658

See merge request !3323

Fix diff image view modes (2-up, swipe, onion skin) not working

Example test case: https://gitlab.com/mrtzcspr/test/commit/5d983226b1308d98ef3d8919b978ad49f34496b8

Closes #13856

See merge request !3316

Use gitlab-workhorse 0.7.1

A small extra defense against interrupted git raw responses. Nice to
have in 8.6 because we introduce /raw/ caching; it would be
unfortunate if incorrect (truncated) responses got cached.

See merge request !3330