Docs for the new branch button

[ci-skip]

Closes #3886 

@axil Could you check this and make sure this is up to your standards?



See merge request !3425

Fix repository cache invalidation issue when project is recreated with an empty repo

See merge request !3692

[ci skip]

API: Ability to update a group

This makes it much easier to update a group after introducing the group visibility.

* Closes #14991 

See merge request !3587

To reproduce:

1. Create a project with some content
2. Rename the project
3. Create a new project with the same name.
4. Boom - 404.

After step 2, the branch and tag counts were not being cleared. This would
cause `repository.has_visible_content?` to erroneously return `true`
for the newly-created project.

Closes #13384

Wrap text in notes box if longer than code in diff

* Fixes branch name overflow
* Text and inline `code` wraps in comments
* `code` blocks scroll horizontally

![Screen_Shot_2016-04-11_at_4.59.15_PM](/uploads/39eee7d35ea79d1a3944aa6281b72121/Screen_Shot_2016-04-11_at_4.59.15_PM.png)

See merge request !3626

Fix todo_target_path for todos where target was removed

Fixes #15187 

See merge request !3684

Update spring and spring-commands-spinach

Spring changelog: https://git.io/vVAUY

See merge request !3681

Fix datetimes on tooltips

Closes #14206 

Updates tooltip datetimes on `.timeago()` instances. 

**Inline notes**

![Screen_Shot_2016-04-07_at_1.25.12_PM](/uploads/2f55390a7e91dabf75e71fe3bda91849/Screen_Shot_2016-04-07_at_1.25.12_PM.png)

**Existing and new notes**

![Screen_Shot_2016-04-07_at_1.24.49_PM](/uploads/202bb7476738eb048f2d94abb68174e7/Screen_Shot_2016-04-07_at_1.24.49_PM.png)


**Issuable dates**

![Screen_Shot_2016-04-07_at_1.24.32_PM](/uploads/80fd5cc3c06fade0b1c615bc7b7611a8/Screen_Shot_2016-04-07_at_1.24.32_PM.png)

**Build dates**

![Screen_Shot_2016-04-07_at_1.25.02_PM](/uploads/832f43284005ea610a3ad54a49b97104/Screen_Shot_2016-04-07_at_1.25.02_PM.png)

See merge request !3497

Spring changelog: https://git.io/vVAUY

Check and report import job status to help diagnose issues with forking

There are no functional changes, but adding checks/logs for Sidekiq job IDs to help track down why many users seem to get stuck fork/import jobs.

See merge request !3672

Project dropdown in header uses new dropdown



See merge request !3339

Fix emoji aliases not showing in autocomplete

closes #14948 

See merge request !3595

Fixed issue with member access not being visible on notes

This happened because the `note-actions`, which houses the access, was wrapped in a `can_edit` if statement

![Screen_Shot_2016-04-08_at_16.02.47](/uploads/40bffe9bb53c015f30ffa93bb018552b/Screen_Shot_2016-04-08_at_16.02.47.png)

Fixes #15049

See merge request !3618

Fix quick submit missing in edit merge request page

closes #14953 

![fix](/uploads/5b80b37330929514c81299b4c8fe3efb/fix.gif)

See merge request !3601

Updated media query for admin/groups search box

@jschatz1 based on your comment https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3523#note_4632743

See merge request !3599

Fixed colour of dropdown link hover

![Screen_Shot_2016-04-07_at_16.02.40](/uploads/bfbfa5d1b82576b6bafaefd567effa06/Screen_Shot_2016-04-07_at_16.02.40.png)

See merge request !3596

Added CHANGELOG item

Fix labels not displayed on todos page

closes #14512,#13920

# For Todos

## Before
![Screen_Shot_2016-03-23_at_8.59.32_PM](/uploads/0c22c7674783031c9be842860082fdc2/Screen_Shot_2016-03-23_at_8.59.32_PM.png)

## After
![Screen_Shot_2016-03-24_at_12.35.06_PM](/uploads/f62d3f39c0aa2f7079368e157a3a558c/Screen_Shot_2016-03-24_at_12.35.06_PM.png)

# For Activity Feed

## Before
![Screen_Shot_2016-03-24_at_12.37.41_PM](/uploads/744370db7a4bd3782c029d80c3694ee7/Screen_Shot_2016-03-24_at_12.37.41_PM.png)

## After
![Screen_Shot_2016-03-24_at_12.37.00_PM](/uploads/9939817c14e98b50b3e16c8b7b9cf009/Screen_Shot_2016-03-24_at_12.37.00_PM.png)

See merge request !3371

Decouple membership and notifications

This allow you to have notification setting per project even if you are member of group. 
It also creates background for having notification settings in project you are not member of. 


- [x] Make it work
- [x] Migrations
- [x] CHANGELOG
- [x] More tests
- [x] API

For #3359 

After this merge request there is still some work to be done: 

* create migration that remove duplicates in notification settings table and create uniq index (8.8 probably)
* remove notification_level field from Member model in 9.0
* make proper API for notification settings
* use `MemberCreateService` instead of Member#after_create callback for creating notification settings (after #14709) 
* maybe more tests 
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

See merge request !3421

Prefills commit message in edit file

See #14488 

![Screen_Shot_2016-04-06_at_10.18.06](/uploads/2ace2a21a6ead8d83c79ef9ce5dd34cc/Screen_Shot_2016-04-06_at_10.18.06.png)

See merge request !3564

Build notification null check

Cancels build notification interval on page change

See merge request !3540

Add proper nil and error handling to SAML login process

While writing the feature that would allow certain Omniauth providers to be marked as external I noticed that there is a scenario where the `gl_user` method can return `nil` and if this is not properly checked, it will lead to exceptions that will cause 500 errors. It is quite easy to land in this scenario, so I added `nil` checks.

I also noticed that the `saml` method in the `omniauth_callbacks_controller.rb` file lacked a `rescue` for `Gitlab::OAuth::SignupDisabledError`, which can happen if the default configuration from `1_settings.rb` is applied. So I also added this check.

See merge request !3609

Fix #14753: Check if head is born before trying to detect main language

This MR makes sure that head exists before trying to detect the main language.
This prevents errors on repo's without a master branch.

Closes #14753

See merge request !3654

Instrument all service classes

This will help us see where (mostly) Sidekiq code is spending time.

See merge request !3675