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

Documents that users with two-factor authentication enabled may also need to create a personal access token to use git over HTTPS.

To address a support issue (gitlab-com/support-forum#980) about why passwords don't work in git when two-factor auth is enabled.

gitlab-com/support-forum#980

See merge request !6616

Increase z index on fixed mr tabs

Before:   
<img src="/uploads/e890a4f185af87b66251d744fbe840d5/Screen_Shot_2016-10-26_at_11.58.45_AM.png" width="400px">

After:   
<img src="/uploads/0bbf72888f6a47bd3027ee7dfff542da/Screen_Shot_2016-10-26_at_11.58.28_AM.png" width="400px">
Closes #23866

See merge request !7124

Add todo toggle event

## What does this MR do?
Adds a custom jQuery event `todo:toggle` to detect when a new todo is added so that the respective todo counters (header navigation and sidebar) can update as needed

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

*  I wasn't sure whether each `spec` should be modularized based on the html templates or whether they should be separated based on function. There are some crossovers between the `dashboard_spec` and the `header_spec`.
* The naming conventions for `sidebar` and `right_sidebar` were a little confusing since they were named the opposite in their `specs`. I made a few assumptions and named a few files based on what I thought they should be named. I'd be happy to change it to something else though :smile:  

## Why was this MR needed?
This resolves an existing issue where the todo count on the sidebar would not update (until refresh) and refactors the existing methods that are used to update the todo counters (header navigation and sidebar)

## What are the relevant issue numbers?
Closes #20140

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- 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 !5724

Remove tooltips from build nodes

Before:   
<img src="/uploads/48441dccfe39c5eb1da3dbb9a26e6bd2/Screen_Shot_2016-10-26_at_2.43.46_PM.png" width="400px">
After:   
<img src="/uploads/d72b2ad4603c964283e155e5a2b053fe/Screen_Shot_2016-10-26_at_2.43.31_PM.png" width="400px">
Closes #23868

See merge request !7128

Create new list dropdown stays open after new list

## What does this MR do?

After creating a new list, the dropdown stays open until the user closes the dropdown themselves.

## Screenshots (if relevant)

![keep-open](/uploads/06580dd552647b1a9e5fabc2c978148b/keep-open.gif)

## What are the relevant issue numbers?

Closes #22852

See merge request !6742

Backups fail occasionally with "tar: ./objects: file changed as we read it" error

- [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
- 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)

Closes #5613

See merge request !5814

Closes #22852

only.