Also added API specs for that

Closes #11853

Currently any spam detected by Akismet by non-members via API will be logged
in a separate table in the admin page.

Closes #5612

This is the git default and will help to prevent false positive matches.

Closes #12706

Since GitHub doesn’t apply these constraints to theirs wiki slug
allowing characters like `,`, `:`, `*`, etc, we need to relax our
constraints or some wiki pages will not be available after they were
imported.

For an example the Devise project have a wiki page with the following
slug: “How To: Add sign_in, sign_out, and sign_up links to your layout
template”

Added also a `Gitlab::Ci::Build::Artifacts::Metadata::ParserError`
exception class.

This reverts nesting artifacts controller in builds module.

Closes #3046

Using the fuzzy filter, develop "file finder" feature.
- feedback(http://feedback.gitlab.com/forums/176466-general/suggestions/4987909-add-file-finder-fuzzy-input-in-files-tab-to-ju )
- fuzzy filter(https://github.com/jeancroy/fuzzaldrin-plus)
- shortcuts(when "t" was hitted at tree view, go to 'file find' page and 'esc' is to go back)
- depends on gitlab_git 7.2.22

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

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

Fix constraints

Updated Sidekiq to 3.5.x