Implement custom notification level options

![Screen_Shot_2016-06-17_at_15.31.43](/uploads/3fc47d2f461b3e8b67bb8acaa304cf99/Screen_Shot_2016-06-17_at_15.31.43.png)

![Screenshot_from_2016-06-15_10-52-27](/uploads/88dbdd21d97e80ee772fe08fa0c9b393/Screenshot_from_2016-06-15_10-52-27.png)

part of #12758 

See merge request !4389

Ensure that group owner cannot request access to a project of their group

## What does this MR do?

It fixes two things:

- 91ad995d69e1a0f8991fd896f1d9febc109273fe Ensure that group owner cannot request access to a project of their group
- ec3ff061148d556757e7cd486cdc6083d77acf34 Ensure group/project owners can see their members' access_level (see the commit message for details)

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

Not really, these are pretty simple fixes.

## Why was this MR needed?

Because there was an issue created!

## What are the relevant issue numbers?

Fixes #18717.

## Does this MR meet the acceptance criteria?

- [x] CHANGELOG is not needed since the bug is only present in a 8.9 RC
- [x] Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4729

# Conflicts:
#	app/controllers/projects/todos_controller.rb

Avoid that GitHub import fails when retrieving Webhooks for non GitHub admins

Closes #18729 

See merge request !4723

[ci skip]

API endpoints for award emoji

Closes #10884 

See merge request !4575

Fixes header vertical centering.

Fixes header centering. 

![ss__2016-05-16_at_5.26.30_PM](/uploads/300b64afc6585023f0e0dbbf721c359a/ss__2016-05-16_at_5.26.30_PM.png)

cc @dzaporozhets 

See merge request !4170

Ensure Todos counters doesn't count Todos for projects pending delete

Use `TodosFinder` instead of `current_user.todos` to filter projects
pending delete on Todos counters helpers.

Counters should not reflect the number of Todos displayed on the tabs.

Fixes #18633

See merge request !4663

Disable the unlink feature for SAML connected accounts (social login).

This disables the ability to manually unlink your SAML account, if you have one connected. In certain scenarios, the only allowed login mechanism can be SAML, and if you unlink your account you will be locked out of the system (configuration dependent).

Fixes #18613

See merge request !4662

Do not check repos without push events

Reduce false positives from automatic repository checks by skipping
projects without push events.

See merge request !4684

Docs also added.

Cache todo counters (pending/done)

See merge request !4438

Fixed issue with assignee dropdown not selecting correctly

## What does this MR do?

Fixes an issue with assignee dropdown not selecting correctly.

See merge request !4762

This only supports Issues and MergeRequests right now because of the
consistency of the routes those models provide.

Fix clipboard buttons on "Check out branch" modal.

Closes #18794 

See merge request !4760

Fixed styling of clipboard button

Closes #18773 

See merge request !4728

Fix a 'wrong number of arguments' error

## What does this MR do?

Fixes #18745.

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

No.

## Why was this MR needed?

To fix #18745.

## What are the relevant issue numbers?

Fixes #18745.

## Does this MR meet the acceptance criteria?

- [ ] Tests
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4757

Track method call times/counts as a single metric

This changes method call tracking so only a single metric is emitted regardless of the number of calls. This allows us to more accurately measure the total execution time of a method as well as the number of times a method is called. See 851e3ff7578973c2206628424eac3b951a3c656d for more details.

Method call tracking tracked calls individually meaning the end statistics may not always be accurate enough to get a good understanding of where time is spent.

See merge request !4754

Re-structured controller spec
Renamed issuable param to issuable_id

Added API endpoint for Sidekiq Metrics.

## What does this MR do?

It adds an API endpoint to gather metrics about Sidekiq, it's jobs, queues, and processes.

## Why was this MR needed?

There was no API endpoint for Sidekiq information.

## What are the relevant issue numbers?

Fixes #7171

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- [x] Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing

See merge request !4653

Also document the clipboard_button_with_class method.

Fixes #18794.

Previously we'd create a separate Metric instance for every method call
that would exceed the method call threshold. This is problematic because
it doesn't provide us with information to accurately get the _total_
execution time of a particular method. For example, if the method
"Foo#bar" was called 4 times with a runtime of ~10 milliseconds we'd end
up with 4 different Metric instances. If we were to then get the
average/95th percentile/etc of the timings this would be roughly 10
milliseconds. However, the _actual_ total time spent in this method
would be around 40 milliseconds.

To solve this problem we now create a single Metric instance per method.
This Metric instance contains the _total_ real/CPU time and the call
count for every instrumented method.

Properly support application/json in Container Registry

## What does this MR do?
When requesting tags a `application/json` is used by `docker/distribution`.

## Why was this MR needed?
Fixes regression introduced by https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4669

## What are the relevant issue numbers?
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18736


See merge request !4742

- As todos are created/updated inside the TodoService
we repopulate the cache just there for both pending/done todos
- Todos as mark as done from the TodosController we update cache
there too
- All the added methods are kept in the User class for cohesion

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

Fix error when editing an issuable with a task list

Closes #18712

See merge request !4751

Filter out sensitive parameters of metrics data

See merge request !4748

- Make it more explicit that `source` must respond to `#group` and that
`#group` must be present.
- Indent subsequent lines of a multi-line condition.
Signed-off-by: Rémy Coutable <remy@rymai.me>

Allow customising of queries used for `update_column_in_batches`

This MR makes two changes to `add_column_with_default` and `update_column_in_batches`:

1. `add_column_with_default` no longer wraps the entire set of updates in a single transaction, preventing any locks from sticking around for the duration of the entire transaction
2. `update_column_in_batches` now takes a block which can be used to customise the queries. This uses Arel as messing with raw SQL strings is a total pain

In !4381 there's a need for updating existing rows/columns in a table in batches using a custom `WHERE` condition. Without the changes in this MR this would not be possible.

See merge request !4680

Upgrade Ruby 2.2 tests to 2.3

This changes the GitLab CI Tests that test compatibility with Ruby 2.2
to instead test compat with Ruby 2.3.

We’ve discussed skipping straight to 2.3.0 when next upgrading the
required Ruby version.

Since Rails 5 requires 2.2.2, and we have to upgrade anyway, may as
well do it now and not risk having to upgrade again come Rails 5.1 or
5.2.

Test failures on Ruby 2.3 do not fail the build.

Related: #12507, #12835 

See merge request !3807