Fix Error 500 when creating global milestones with Unicode characters

Two issues:

1. The constraints in the resources were incorrect. Here's what it was before:

```
group_milestone  GET /groups/:group_id/milestones/:id(.:format)  groups/milestones#show {:id=>/[a-zA-Z.0-9_\-]+(?<!\.atom)/, :group_id=>/[a-zA-Z.0-9_\-]+(?<!\.atom)/}
```

In this case, id is actually the title of the milestone, which can be anything at the moment.

After:
```
group_milestone  GET /groups/:group_id/milestones/:id(.:format)  groups/milestones#show {:id=>/[^\/]+/, :group_id=>/[a-zA-Z.0-9_\-]+(?<!\.atom)/}
```

2. `parameterize` would strip all Unicode characters, leaving a blank string. Rails would report something like:

```
ActionView::Template::Error (No route matches {:action=>"show", :controller=>"groups/milestones", :group_id=>#<Group id: 48, name: "ops-dev", path: "ops-dev", owner_id: nil, created_at: "2015-11-15 08:55:30", updated_at: "2015-12-02 06:23:26", type: "Group", description: "", avatar: "sha1.c71e73d51af1865c1bbbf6208e10044d46c9bb93.png", public: false>, :id=>"", :title=>"肯定不是中文的问题"} missing required keys: [:id]):
```

This change uses the babosa library to create a better slug, which surprisingly
isn't actually used by the global milestone controllers. Instead, they use the
title passed as a query string for some reason.

Closes https://github.com/gitlabhq/gitlabhq/issues/9881

See merge request !1983

fixed the documentation of the Guest role in permission.md

This MR fixes the documentation of the Guest role.

closes gitlab-org/gitlab-ce#3777

[ci skip]

See merge request !1952

Fix application settings cache not expiring after changes

cache_key is an instance method that relies on updated_at. When changes
were made, the time-dependent key was being used instead of X.application_setting.last.

Closes #3609

See merge request !1972

Show Gmail actions links only on expected set of emails



See merge request !1901

Install gitlab-shell 2.6.8 in installations from source

[ci skip]

See merge request !1932

Fire update hook from GitLab

https://gitlab.com/gitlab-org/gitlab-ce/issues/3069

See merge request !1882

[ci skip]

See merge request !1916

Fix Error 500 when viewing user's personal projects from admin page

This is a regression introduced in 4d7f00fd.

Closes #3680

Closes https://github.com/gitlabhq/gitlabhq/issues/9861

Closes gitlab-org/gitlab-ee#90

See merge request !1909

Nginx workhorse upload limit

See merge request !1919

Bump gitlab-shell to 2.6.8 in stable
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

For gitlab/gitlabhq#2635

See merge request !1940

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

Maybe rescue session_expire_delay by setting a default value.

Related to gitlab-org/omnibus-gitlab#956

See merge request !1880

Update required version of lfs client and separate the docs for users and admins.



See merge request !1855

Expose artifacts path

This fixes broken artifacts storage path.

Fixes #3607 
Fixes #3608

Related: gitlab-org/omnibus-gitlab!544

See merge request !1869

[ci skip]

Fix 500 when using CI

- Fix for Ci::Build state machine, allowing to process builds without the project
- Forcefully update builds that didn't want to update with state machine
- Fix saving GitLabCiService as Admin Template

Fixes #3556 

See merge request !1873

Fix CSS styling for clipboard icon in new MR page

Closes #3602 

See merge request !1870

Emoji bug: Invalid url to image

Closes #3591

See merge request !1868

Handle removed source projects in MR CI commits

Fixes #3599 

@dzaporozhets assigning this to you since you wrote the original code. Perhaps checking for the source project isn't the right way, but I'm not sure if there's a better way (e.g. somewhere earlier in the process) that we can detect this.

See merge request !1859

Add upvote/downvote fields to merge request and note API to preserve compatibility

As discussed in !1825 we should not break the API compatibility.

* This MR adds the fields `upvotes`/`downvotes` to the merge request API again, which always return `0`.
* Add the fields `upvote`/`downvote` to the notes API, which always return `false`

This behavior is documented in the API docs.

See merge request !1867

Make tag API for release feature consistent

Make tags API consistent with other tags methods. This changes the endpoint from `PUT /projects/:id/repository/:tag/release` to `PUT /projects/:id/repository/tags/:tag_name/release`.

On thing the API is still missing, is an error if the tag does not exist. Right now it returns 200 even the tag does not exist. I'll fix that such it returns 404.

@stanhu Can you review?
@rspeicher This MR should go into 8.2

See merge request !1864

Award Emoji: fix for merge requests

Closes #3597

See merge request !1865

[ci skip]

Remove accidentally added line.

Reference: #3598 

See merge request !1858

Fix Drone web hook URL not being updated

Fixes regression of !1774: fixes Drone Web hook for both service templates and project services.



See merge request !1856

Use award emoticons in GitLab workflow

Remove the old voting slides and use the emoji bar.

[ci skip]

See merge request !1863

Add tags page to readme

The tags page was separated for the release feature but not to the index readme.

[ci skip]

See merge request !1861

Bump GitLab Workhorse version to 0.4.2



See merge request !1830

Lfs batch download to stable

!1842 for stable

See merge request !1853

Lfs on by default and backup



See merge request !1852