Update links in side nav and header

* Remove todos, help, and project settings from sidebar
* Remove plus icon from top right header
* Put help link in user dropdown
* Add lighter bg-color at the top of side nav

![Screen_Shot_2016-10-27_at_3.42.55_PM](/uploads/d81f3135b1af1e580d62451ae83b3435/Screen_Shot_2016-10-27_at_3.42.55_PM.png) 
Closes #22889

See merge request !7161

Support for post deployment migrations

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/22133

See merge request !6572

Adds label description to issue board title

## What does this MR do?

Adds the label description as a tooltip the issue board title. Tooltip is not visible on the backlog or done list.

## Screenshots (if relevant)

![tooltip-title](/uploads/e807a7ff6c48ac2181c4d4e86adf0f77/tooltip-title.gif)

## What are the relevant issue numbers?

Closes #22710

See merge request !6743

Hide project activity tabs when features are disabled

## What does this MR do?

When features are disabled in project settings, the activity tabs are now correctly hidden.

## Screenshots (if relevant)

![Screen_Shot_2016-10-21_at_12.15.27](/uploads/3d85c027aa05487001c8abd624a99be0/Screen_Shot_2016-10-21_at_12.15.27.png)

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/19734#note_17224181

See merge request !7038

Remove tooltips from project header

Closes #23641

See merge request !7211

fix how to get SAML error details

## What does this MR do?

Update to better document how to get SAML error details.

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/1929 and https://gitlab.com/gitlab-org/gitlab-ce/issues/3223. Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/12705.

See merge request !7199

Initialize Sidekiq with the list of queues used by GitLab

See merge request !7217

Add validation errors to Merge Request form

Closes #22448

See merge request !7163

Allow admin to search for user by secondary email address

Closes #23761

See merge request !7115

New todos blank state

## What does this MR do?

Updates the blank state on todos.

### Blank state when user has previously had todos

![Screen_Shot_2016-10-12_at_12.40.35](/uploads/17d9a5a409d12bce73147e3879d9d62d/Screen_Shot_2016-10-12_at_12.40.35.png)

### Fully empty blank state

![Screen_Shot_2016-10-12_at_12.40.40](/uploads/5c0824096ced9f03b3ea5f892b70b08b/Screen_Shot_2016-10-12_at_12.40.40.png)

## What are the relevant issue numbers?

Closes #20833

See merge request !6823

Remove leftover references to coffeescript from comments and docs.

I was looking at the front-end helper spec and noticed some outdated coffeescript refs in it. So I figured it wouldn't hurt to take a few minutes and remove all the coffeescript references in CE that we don't need anymore. 

I didn't touch any coffeescript references that could potentially break anything. Just docs and code comments.

- [x] All builds are passing

See merge request !7151

It is not possible to search for a user by his secondary email address in
the Users search bar in the admin interface(/admin/users). A use-case could
 be that an admin wants to remove a specific secondary email address of an
user, because it interferes with another user. Issue #23761

This commit adds ability to search not only by main email, but also
by any secondary email in the admin interface.

The parameter is used to search users by several criretia was
called :name. This request renames it to :search_query which closer
to it actual perpose

Fix project features default values

closes #23242

See merge request !7181

Correct padding and alignment for reaction buttons

## What does this MR do?
Fixes padding and alignment for reaction buttons on issues.

## Screenshots (if relevant)

### Before
![img](https://gitlab.com/gitlab-org/gitlab-ce/uploads/ae788883aca84799fca9cd23f8e16f28/image.png)
![img](https://gitlab.com/gitlab-org/gitlab-ce/uploads/b2f5aa45dbb4899f054f839bd9046bb6/image.png)

### After
![Screen_Shot_2016-10-28_at_3.56.03_PM](/uploads/0b1affed448f6ec24fa56e7800daf753/Screen_Shot_2016-10-28_at_3.56.03_PM.png)
![Screen_Shot_2016-10-28_at_3.56.09_PM](/uploads/311bb59dc6eea8cd124232ebe647b5ef/Screen_Shot_2016-10-28_at_3.56.09_PM.png)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) 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 [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] 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 it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #23918

See merge request !7182

Fix relative links in Markdown wiki when displayed in "Project" tab

Refers to #23806

See merge request !7218

The Sidekiq client API adds an entry to the Sidekiq "queues" list,
but mail_room and gitlab-shell use redis-rb directly to insert jobs
into Redis and thus do not make an extra "sadd" call to Redis
each time a job is inserted. To make it possible to monitor
these queues via the API, add an initialization step to
set up the list at startup.

Closes gitlab-com/infrastructure#682

Implement CreateProjectMembers service to make controller thin

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/23566

See merge request !7170

Add a link to the Issue Boards API in main README

See merge request !7221

[ci skip]

Blacklist the OSL 3.0 license

See merge request !7171

Do not show tooltip for active element

## What does this MR do?

Change Bootstrap's default for tooltips to display them only when hovering and not for the active element.

See also here: https://getbootstrap.com/javascript/#tooltips-options

## Screenshots

### Before

![before](/uploads/c5b7bd9eba07ca61bfa5ba014d08dd1a/before.webm)

### After

![after](/uploads/d8c4a69e5a6797d8d26ab92cb96fcb2d/after.webm)

## What are the relevant issue numbers?

Closes #23794

See merge request !7105

If source branch or target branch doesn't exist in the project, display
form validation errors. Previously, this caused a 500 error code.

Fix Markdown styling inside reference links

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/18096.

Based off https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6609.

See merge request !7169

Fix project visibility level link

Fix wrong syntax for link generation.

See merge request !7201

Update tags.md

See merge request !7202

Fixes: https://gitlab.com/gitlab-org/gitlab-ce/issues/18096

Refers to #23806.

Closes #22710

Optimize group labels page

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/23684

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/1148

See merge request !7123

Closes #20833