Fix atom feeds and links

1. The atom feed for a group's issues didn't work, because it had parts copied from the dashboard issues builder template.
2. The feed link from a group's activity page went to the dashboard feed, rather than the group's feed.

Closes #15640

See merge request !4191

Fix broken link in CI quickstart docs

The newline between the `[label]` and the `(link)` caused it to be interpreted literally: http://doc.gitlab.com/ce/ci/quick_start/README.html

See merge request !3541

Improve issue formatting in Slack service

This will improve the looks of the message that gets send to Slack.

**Before**

![image](https://gitlab.com/jeroenvanbaarsen/gitlab-ce/uploads/670442d4d5cef5aa36753671b8894a75/image.png)

**After**

![image](https://gitlab.com/jeroenvanbaarsen/gitlab-ce/uploads/ab6e40a0c22ebe89ebd5b3652821c6dd/image.png)

There is one thing I'm not certain about, thats sending the logo with the payload. Because this means we need to host the GitLab logo somewhere public, and every time a payload from any GitLab instance is send, we use that logo url. This might overload the server, or drive the bandwidth bill through the roof.
This is something @sytses or @dzaporozhets have to decide about.

@stanhu, you told me you were the author of the original code, maybe you can review?

See merge request !1308

Fixed typo in zen.scss and corresponding views



See merge request !4045

Make it clearer that /licenses is the OS license templates endpoint

Following the discussion on https://gitlab.com/gitlab-org/gitlab-ce/commit/13804aba867d19009ca94d820aa7ec650a509f5a#note_4961954.

Corresponding EE MR: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/407

See merge request !4188

Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>

Clean up the images from GitLab CI

Closes #17568

See merge request !4163

Remove bottom margin for flash message on home page

### Flash Messages 
Remove `margin-bottom: 16px` from `.no-ssh-key-message` and `.project-limit-message`. 
This added an unnecessary margin between the notification and the content which was brought up in this issue #14797.

### Affected files:
    ./app/assets/javascripts/project.js.coffee:      $(@).parents('.no-ssh-key-message').remove()
    ./app/assets/stylesheets/pages/projects.scss:.no-ssh-key-message, .project-limit-message {
    ./app/views/shared/_no_ssh.html.haml:  .no-ssh-key-message.alert.alert-warning.hidden-xs
    ./app/assets/javascripts/user.js.coffee:    $('.hide-project-limit-message').on 'click', (e) ->
    ./app/assets/javascripts/user.js.coffee:      $(@).parents('.project-limit-message').remove()
    ./app/assets/stylesheets/pages/projects.scss:.no-ssh-key-message, .project-limit-message {
    ./app/views/shared/_project_limit.html.haml:  .project-limit-message.alert.alert-warning.hidden-xs
    ./app/views/shared/_project_limit.html.haml:      = link_to 'Remind later', '#', class: 'hide-project-limit-message alert-link'

### Screenshots:
#### Before: 
![Screen_Shot_2016-05-16_at_11.45.17_PM](/uploads/35f9db16526830e49bc302e2d00ecf7e/Screen_Shot_2016-05-16_at_11.45.17_PM.png)

#### After:
![Screen_Shot_2016-05-16_at_11.38.24_PM](/uploads/b8f9ac29b574a99c962c52028f7e61dd/Screen_Shot_2016-05-16_at_11.38.24_PM.png)


See merge request !4173

[ci skip]
Signed-off-by: Rémy Coutable <remy@rymai.me>

Create import data in service and fix timing issues when scheduling job

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/17401

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/17376

See merge request !4106

This was using the user dashboard atom builder template, not one for the
group's issues.

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

Fix api leaking notes when user is not authorized to read noteable

fixes #17302

See merge request !4102

fix typo making gitlab.com importing to fail

Fixes https://gitlab.com/gitlab-org/gitlab-ee/issues/565

See merge request !4181

Instrument all Grape API helpers

This has been added to help us figure out what's making certain Grape API calls slow (e.g. the one used for authorized keys as described in gitlab-com/operations#99).

See merge request !4169

Fix left sidebar overlap when scroll on long menu

Fixes #17566. Caused by https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4139. Smaller fix compared to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4164

cc @iamphill @jschatz1 
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

See merge request !4165

Toggle email signup confirmation in admin settings

Implements toggling verification email #14684

See merge request !3862

Add an Event's target's title to its reference link

Given an activity feed entry like:

> Douwe Maan commented on [issue #123] at [gitlab-org/gitlab-ce]

...the `issue #123` link will now have a `title` attribute.

Plus some minor refactorings, see individual commits for details.

See merge request !4090

Disallow search engines from indexing uploads from a GitLab project.

This can sometimes include sensitive information from private projects and confidential issues. It shouldn't be indexed. Resolves #15551.

cc: @DouweM 

See merge request !4167

Use the relative url prefix for links in Wiki

Retry of gitlab-org/gitlab-ce!4026

@rymai !4050 solved all other problems how it looks like. I [tested](https://gitlab.com/artem-forks/gitlab-ce/commit/ff01eca7b559efa7cacf3412aa01cd8ae8a6db7e/builds) this with ruby22

Fixes #17071 



See merge request !4131

Add tests for unintentional filtering bug in MR

!3872 has a lack of tests for Merge Requests while !3872 has only ones for Issues.

This MR has complementary tests for MR list.

See merge request !4154

This can sometimes include sensitive information from private projects and confidential issues. It shouldn't be indexed. Resolves #15551.

Remove unused methods from Event model

These get escaped automatically.

Prior, the `title` attribute was being included as an argument to the
route helper rather than as an argument to `link_to`.

Given an activity feed entry like:

> Douwe Maan commented on [issue #123] at [gitlab-org/gitlab-ce]

...the `issue #123` link will now have a `title` attribute.

Merge branch '17227-upcoming-milestone-is-confusing-when-projects-have-different-milestones' into 'master'

Make upcoming milestone work across projects

Before: we took the next milestone due across all projects in the
search and found issues whose milestone title matched that
one. Problems:

1. The milestone could be closed.
2. Different projects have milestones with different schedules.
3. Different projects have milestones with different titles.
4. Different projects can have milestones with different schedules, but
   the _same_ title. That means we could show issues from a past
   milestone, or one that's far in the future.

After: gather the ID of the next milestone on each project we're looking
at, and find issues with those milestone IDs. Problems:

1. For a lot of projects, this can return a lot of IDs.
2. The SQL query has to be different between Postgres and MySQL, because
   MySQL is much more lenient with HAVING: as well as the columns
   appearing in GROUP BY or in aggregate clauses, MySQL allows them to
   appear in the SELECT list (un-aggregated).

Closes #17227.

See merge request !4125