Allow membership override when using LDAP group sync

Backend part of #343 

Adds an `ldap` and `override` attribute to `Member` so we can track which members are managed by LDAP and if/when they're overridden.

- `Member#ldap?` will tell you whether it's an LDAP member 
- `Member#override` should be set to `true` if someone adds an override. Sync will then ignore it, until `Member#override` is set back to `false`.

## Performance testing

All tests resulted in approximately 119,000 total members being created. 


-  ✅ 19 minutes - An 'update' sync (where all members already existed) updating the `ldap` flag once.
- ✅ 79 minutes - A full, fresh sync before changes
- ✅ 76 minutes - A full, fresh sync after changes

Although the before time was actually higher than the after time, I think there's a standard deviation in there that accounts for it. The important thing is that it's not drastically different. 

See merge request !717

Improve ES logging



See merge request !725

Notified via email



See merge request !732

CE upstream

Pulled CE changes https://gitlab.com/gitlab-org/gitlab-ce/compare/5533fd17d86e377effc8dad7ca0ac5fcb8bbebed...13bb9ed77f405c5f6ee4fdbc964ecf635c9a223f

See merge request !729

ES: Global code search

- [x] Basic implementation of blobs search
- [x] Basic implementation of commits search
- [x] Fix pagination for commits. Do paginating on ES level instead of resulting array
- [x] Refactoring. The `gitlab-elastcsearch-git` gem should not know anything specific to GitLab application structure.
- [ ] Backport changes to CE
   - [ ] Search result parsers (after review this MR)
   - [x] Removing `total_count` (https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6216)
- [x] Make rake tasks pass parent id
- [x] Test database search afterwards
- [x] Mention somewhere that ES should be updated to 2.4.0
- [x] Specs
- [x] Address TODO in the code
- [x] Add project name to search results

Related MR for `gitlab-elasticsearch-git` gem (https://gitlab.com/gitlab-org/gitlab-elasticsearch-git/merge_requests/18)

Screenshots:

![Screen_Shot_2016-09-06_at_16.07.30](/uploads/dca09ee14b9c728ab22b902ed471a071/Screen_Shot_2016-09-06_at_16.07.30.png)

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/556

See merge request !699

Merge branch '939-repositoryupdatemirrorworker-updatemirrorerror-rugged-invaliderror-cannot-set-empty-url' into 'master'

Fix mirrored projects allowing empty import urls

Because of missing validations in the projects model, you could
create a new project with a nil or empty import_url with mirror=true.
This would cause exceptions when
RepositoryUpdateMirrorWorker::UpdateMirrorError ran and attempted to
update one of these projects. This was made easier by the fact that
you could show the "Mirror repository" checkbox in the UI, check it,
hide it, and still have its value considered.

The missing validations have been added, and minor adjustments have
been made to the UI to improve the previous behaviour. A migration
was also added to update mirror=false in all projects with a nil or
empty import url that exists because of the described bug.

Closes #939

See merge request !700

Because of missing validations in the projects model, you could
create a new project with a nil or empty import_url with mirror=true.
This would cause exceptions when
RepositoryUpdateMirrorWorker::UpdateMirrorError ran and attempted to
update one of these projects. This was made easier by the fact that
you could show the "Mirror repository" checkbox in the UI, check it,
hide it, and still have its value considered.

The missing validations have been added, and minor adjustments have
been made to the UI to improve the previous behaviour. A migration
was also added to update mirror=false in all projects with a nil or
empty import url that exists because of the described bug.

Refactor the license documentaiton

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/1000

See merge request !730

Request only the LDAP attributes we need

## What does this MR do?

It includes CE changes from https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6187 to reduce the chance of merge conflicts since lots of stuff moved around. 

Fixes gitlab-org/gitlab-ce#13821. For LDAP users, we really only ever need uid, dn, cn, and mail attributes, and in some cases, even less. For LDAP groups we need ..... This merge request strips the request down to the minimum needed by default, and allows the caller to specify more or less, if needed. 

## Why was this MR needed?

This will improve performance especially in cases where the connection is slow between GitLab and LDAP, or when the LDAP object has lots of attributes we don't care about.

See merge request !712

Fix: Elasticsearch does not find partial matches in project names

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/960

See merge request !726

Reduce UPDATE queries when moving between import states on projects

See merge request !723

Fix spec in master

Fixes failed builds such as https://gitlab.com/gitlab-org/gitlab-ce/builds/3919501

cherry-picked form https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6291

See merge request !728

Fixes failed builds such as https://gitlab.com/gitlab-org/gitlab-ce/builds/3919501

Pull import sources from Gitlab::ImportSources

## What does this MR do?
`ApplicationSettings.create_from_defaults` defines an array of import sources, but we should be pulling them from `Gitlab::ImportSources.options` since that's what they're validated against.

## What are the relevant issue numbers?

Closes #21814

See merge request !6293

Improve PipelinesFinder spec so that it does not depend on hard-coded database IDs

Fixes failed builds such as https://gitlab.com/gitlab-org/gitlab-ce/builds/3919501

See merge request !6291

Fixes failed builds such as https://gitlab.com/gitlab-org/gitlab-ce/builds/3919501

Enable pipeline events by default

This should probably be included in !5620 but missed.

See merge request !6278

Restrict ldap return attributes

## What does this MR do?

Fixes the CE part of #13821. We really only ever need uid, dn, cn, and mail attributes, and in some cases, even less. This merge request strips the request down to those four attributes by default, and allows the caller to specify others, if needed. 

## Why was this MR needed?

This will improve performance especially in cases where the connection is slow between GitLab and LDAP, or when the LDAP object has lots of attributes we don't care about.

See merge request !6187

Add update guide for 8.12 CE to EE.

[ci skip]

See merge request !706

Pass the remember_me option into the u2f form and support it while authenticating

## What does this MR do?

Adds remember me support in the u2f authentication, and makes sure the flag gets passed from the login form to the u2f form.

Based on the changes for the same thing done for regular 2fa: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4369

## Why was this MR needed?

The remember me option wasn't working for u2f devices (yubikey)

## What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18103

See merge request !5918

Archive CHANGELOG entries prior to 8.0 in CHANGELOGS/archive.md

[ci skip]

See merge request !6162

See gitlab-org/release-tools!29

[ci skip]

[ci skip]

Hides merge request button on branches page

## What does this MR do?

 If user does not have the correct permissions, the merge request button is hidden

## What are the relevant issue numbers?

Closes #21805

See merge request !6181

By changing our logic from `before_transition` to `after_transition`
blocks and removing extra calls to `update` or `save` we can do all
changes in a single UPDATE query (currently each transition change
from started -> failed and started -> finished runs two UPDATE
queries each)