Add environments and deployments

This MR is a continuation of https://gitlab.com/gitlab-org/gitlab-ce/issues/17009.

The current implementation is as follow:
1. We have two new tables: `environments` and `deployments`.
2. We have a new tab: `Environments` under `Pipelines` where you can see all you environments and add a new one.
3. We add a new option to `.gitlab-ci.yml` to track where we should create a deployment for environment.
4. If environment in `.gitlab-ci.yml` is specified it will create a deployment. **If environment does not exist it will be created.** (this got changed)
5. The deployment is always successful and shows the time of the action, in that case a build that presumably should do deployment. In the future we could extend deployment with statuses: success, failure. We could extend deployments with information that this is partial or full deployment.
6. User have to create environments that he will track first.
7. User can remove environments.
8. User can retry/rollback past deployment (in that case we retry past build). The new build when succeeds it will create a new deployment.
9. Currently environment have only one parameter: `name`. In the future it should have: `variables`, `credentials` and possibly `runners` and maybe other resources.
10. Currently deployment have this parameters: `sha`, `ref`, `deployable (in this case a build)`, `user (who triggered a deployment)`, `created_at`.

The `.gitlab-ci.yml`:
```
deploy to production:
  stage: deploy
  script: dpl travis...
  environment: production
```

What needs to be done:
- [x] Write initial implementation
- [x] Improve implementation (@ayufan)
- [x] Write tests (@ayufan)
- [x] Improve UX of the forms (cc @markpundsack) - reviewed by @markpundsack
- [x] Improve implementation of the views (cc @jschatz1) - done by @iamphill 
- [x] Write .gitlab-ci.yml documentation for `environments` - done by @ayufan
- [ ] Write user documentation (@ayufan and @markpundsack)

See merge request !4605

Seed Award Emoji while seeding the database

## What does this MR do?

Lets `rake dev:setup` create award emoji on _some_ awardables. Seemed overkill to give all that privilege. 

See merge request !4555

Fix the logo in header not being an anchor link.

## What does this MR do?

Adds an actual link to the Tanuki in the header instead of a `Turbolinks.visit()`.

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

Do we care that this reverts the Safari issue fixed in !2690? I feel bad, but it's hacky and there's not a great way to fix it here.

## Why was this MR needed?

You couldn't open the home page in a new tab before, it was very annoying.

## What are the relevant issue numbers?

Fixes #18604 

cc: @rspeicher 

See merge request !4661

Fixed issue with move dropdown not being searchable

## What does this MR do?

Adds the ability to search the project move dropdown.

## What are the relevant issue numbers?

Closes #18634 

## Screenshots (if relevant)

![search](/uploads/f10a9a16b608308c1b3c66f186f57f80/search.gif)

See merge request !4666

This is done to make belongs_to with required to properly validate association.
Otherwise `ActiveRecord::StatementInvalid` is raised.

Don't allow U2F set up unless an authenticator app is set up

Closes #17333 

# TODO

- [ ]  #17333 Authenticator should be set up before enabling U2F
    - [x]  Implementation
    - [x]  Fix/add tests
    - [x]  Refactor
    - [x]  Wait for [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/964c98a3c427cac6e3de88ddc74a9f172ee9742d/builds) to pass
    - [x]  Assign to endboss for review
    - [x]  Address @DouweM's comments
        - [x]  No need for `javascript:void(0)`
        - [x]  Add screenshots
    - [ ]  Wait for merge

# Screenshots

![Screen_Shot_2016-06-15_at_8.18.03_AM](/uploads/26531fa7f6e5d7617fd11d1779021b4f/Screen_Shot_2016-06-15_at_8.18.03_AM.png)
![Screen_Shot_2016-06-15_at_8.18.37_AM](/uploads/ceaae97a987a15d3e04dd76aa8a944bd/Screen_Shot_2016-06-15_at_8.18.37_AM.png)
![Screen_Shot_2016-06-15_at_8.18.47_AM](/uploads/394224d5fcff759d5acc3bf39a138530/Screen_Shot_2016-06-15_at_8.18.47_AM.png)

See merge request !4585

Resolve "Track the number of new Redis connections per transaction"

## What does this MR do?

Add a new metric counter, `new_redis_connections`, that contains the number of calls to `Redis::Client#connect` in the current transaction.

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

Not sure. I tested this in kind of a brute-force way:

1. Add a debugger in the monkey-patched `connect` method.
2. With metrics enabled, start the app and load a page.
3. The first Redis connection is created by `Rack::Attack` and isn't in a transaction, but still works fine.
4. The second Redis connection is within a transaction (the page load), and increments the counter.
5. If I reload the page, neither debugger is hit.
6. If I use a Redis client and do `CLIENT KILL` on my two existing clients, then reload the page, I get 3 and 4 again.
7. If I disable metrics collection, the debugger never gets hit.

## Why was this MR needed?

We may have a Redis connection leak somewhere, so adding metrics will let us track this.

## What are the relevant issue numbers?

Closes #18451.

## Screenshots (if relevant)

Hahaha nope, not relevant.

## 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 [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)

cc @yorickpeterse 

See merge request !4649

Add docs for assigning labels/milestone when moving issue

Extends https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3934

See merge request !4069

[ci skip]

Document CI_BUILD_TOKEN

## What does this MR do?

Adds `CI_BUILD_TOKEN` to CI variables documentation.


See merge request !4664

Include user relationship when retrieving award_emoji

See merge request !4647

Closes #18634

Avoiding N+1 when showing grouped awards and when 
calculating participants for awardable entities

Don't fail builds for projects that are deleted when they are stuck

## What does this MR do?

Solves when dropping stuck connection.
```
Dropping stuck pending build 1545510 for runner 
NoMethodError: undefined method `origin_merge_requests' for nil:NilClass
    from /opt/gitlab/embedded/service/gitlab-rails/app/services/merge_requests/base_service.rb:50:in `merge_request_from'
    from /opt/gitlab/embedded/service/gitlab-rails/app/services/merge_requests/base_service.rb:57:in `each_merge_request'
    from /opt/gitlab/embedded/service/gitlab-rails/app/services/merge_requests/add_todo_when_build_fails_service.rb:5:in `execute'
    from /opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/metrics/instrumentation.rb:164:in `execute'
    from /opt/gitlab/embedded/service/gitlab-rails/app/models/commit_status.rb:51:in `block (2 levels) in <class:CommitStatus>'
    from /opt/gitlab/embedded/service/gem/ruby/2.1.0/gems/state_machines-0.4.0/lib/state_machines/eval_helpers.rb:79:in `call'
...
```

This happens, because that `default_scope` of `Projects` filters returns the projects that are not deleted, where `Ci::Build` doesn't take into account.


See merge request !4609

- We added a `current_user.two_factor_via_otp?` check to the view. When
  rendering the view via the teaspoon fixture, `current_user` is `nil`.

- Also change the help message to indicate that an authenticator app is
  now a prerequisite for U2F.

Fix typo in obtaining a backtrace from all threads in gdb



See merge request !4612

Fix note polling when a window has been hidden

`refresh` was called, `refreshing` was set to true, but then because
`document.hidden` was true, `getContent` was never called, and
`refreshing` never got reset to `false`, which stopped polling entirely
until refresh.

See merge request !4635

Manually create todo for issuable

## What does this MR do?

Adds a button to the sidebar in issues & merge requests to allow users to manually create a todo item themselves.

## What are the relevant issue numbers?

Closes #15045 

## Screenshots (if relevant)

![Screen_Shot_2016-06-07_at_09.52.14](/uploads/00af70244c0589d19f241c3e85f3d63d/Screen_Shot_2016-06-07_at_09.52.14.png)

![Screen_Shot_2016-06-07_at_09.52.06](/uploads/e232b02208613a4a50cff4d1e6f119ff/Screen_Shot_2016-06-07_at_09.52.06.png)

![Screen_Shot_2016-06-07_at_09.51.14](/uploads/f1d36435d49ab882538ae2252bec8086/Screen_Shot_2016-06-07_at_09.51.14.png)

See merge request !4502

Only show notes through JSON on confidential issues that the user has access to

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18535

See merge request !1970

Update CHANGELOG

## What does this MR do?
Updates the CHANGELOG


See merge request !4549