Allow admins to disable 2FA for a user

> ![Screen_Shot_2015-07-10_at_5.19.13_PM](https://gitlab.com/gitlab-org/gitlab-ce/uploads/3f9bb7c783110d2689c282879cb4b061/Screen_Shot_2015-07-10_at_5.19.13_PM.png)

Depends on !961

See merge request !962

Add User#disable_two_factor!

This method encapsulates all the logic for disabling 2FA on a specific
User model.

See merge request !961

Fix transferring of project to another group using the API.

Addresses internal issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2397.

See merge request !926

Only enable HSTS header for HTTPS and port 443

### What does this MR do?

This MR adds a check that the port used is 443, in addition to HTTPS being enabled, when activating the HSTS header.

### Why was this MR needed?

If a user is using a non-standard port for SSL, enabling this header would send clients to port 443 when that port is invalid.

### What are the relevant issue numbers?

Closes https://github.com/gitlabhq/gitlabhq/issues/9449

See merge request !966

Closes https://github.com/gitlabhq/gitlabhq/issues/9449

Implement faster search of code (via git grep)

Much faster than iterating over each file using rugged.

Performance compare for Linux repository using keyword `sha`:

```
OLD: 250 seconds
NEW: 9 seconds
```

See merge request !957

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Better handle unknown projects and groups for autocomplete

While working on !963, I noticed that specifying an unknown project ID or group ID would cause an error in the controller. This MR improves on the handling of unknown projects or groups:

1. If the user is authenticated, return a blank JSON with a 404 error.
2. Otherwise, redirect the user to login so we don't leak information about whether certain projects/groups exist.

See merge request !964

Fix typo and remove duplicate entry shipped in v7.12.2

See merge request !965

Fix user autocomplete for unauthenticated users accessing public projects

Closes #1955

See merge request !963

Closes #1955

Do not add the same icon multiple times to dropzones

Some DOM queries were to broad which caused paperclip icons and spinners
to be added multiple times to a dropzone in case of multiple dropzones
on a page.

![gitlab-dropzone-icon-bug](https://gitlab.com/dgerhardt/gitlab-ce/uploads/23e558a375cece21cc7af410e3839e05/gitlab-dropzone-icon-bug.png)

Steps to reproduce:
1. Open an existing issue or merge request with comments.
2. Move a file over the new comment dropzone. One paperclip icon should appear.
3. Now click the edit button for an existing comment and repeat step 2. You should see two paperclips.

Fixes #1725.

See merge request !959

This method encapsulates all the logic for disabling 2FA on a specific
User model.

information about why we use fig.yml

Because of tweet https://twitter.com/nicholasruunu/status/619533541605539841

cc/ @sytses @ayufan

See merge request !960

Added link to issue closing pattern documentation in milestones doc

Added link from Milestones doc to Issue closing pattern because I think they can be useful. Because of Tweet https://twitter.com/steenwijkict/status/619210265008205824

cc/ @sytse 

See merge request !1895

Some DOM queries were to broad which caused paperclip icons and spinners
to be added multiple times to a dropzone in case of multiple dropzones
on a page.

Conflicts:
	docker/marathon.json

Fix migrating from SVN document link

Closes #1959

See merge request !958

Closes #1959

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Smaller font and leing height for sidebar elements

Recently we added few more entries to project sidebar navigation making it overflow on laptops

1280x720 resolution now:

![Screenshot_2015-07-10_15.34.52](https://gitlab.com/gitlab-org/gitlab-ce/uploads/19f5c77e5d19cf935a4323a079020f7b/Screenshot_2015-07-10_15.34.52.png)

After this fix:

![Screenshot_2015-07-10_15.34.35](https://gitlab.com/gitlab-org/gitlab-ce/uploads/ca9cdcc2ce9c9b6aabb823ba64a3a30a/Screenshot_2015-07-10_15.34.35.png)

This should help for people who use scaling with retina or owners of MacBook Air laptops

cc @JobV

See merge request !955

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Make edit/remove label buttons smaller

## Before

![Screenshot_2015-07-10_14.29.46](https://gitlab.com/gitlab-org/gitlab-ce/uploads/bc7a4886997ab194c1213f38f163b269/Screenshot_2015-07-10_14.29.46.png)

## After

![Screenshot_2015-07-10_14.31.09](https://gitlab.com/gitlab-org/gitlab-ce/uploads/ebb386a38e264ca7b50dc08891cb919c/Screenshot_2015-07-10_14.31.09.png)

See merge request !954

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Forks should not have more permissive visibility levels than the original

https://dev.gitlab.org/gitlab/gitlabhq/issues/2286

See merge request !936