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: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

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

Signed-off-by: Dmitriy 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

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: Dmitriy 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: Dmitriy 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: Dmitriy 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

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

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

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

This reverts commit 57ec2832.

Point to ci.gitlab.com badge in README



See merge request !1893