* master: (23 commits)
  Use single spaces
  Improvements to profile page UI
  Replace all usages of `git` command with configurable binary path
  Update Shell Commands doc for configurable git binary path
  Minor reformatting for Facebook integration doc
  Use proper labels for OAuth providers
  Add Facebook authentication
  Bump stamp to ~> 0.6.0
  Add extra padding between user description and links on profile page
  Fix tests
  Fix clipboard button overflow
  Apply new design for user profile page
  Improve profile page UI
  Better name for up-level links
  Fixed User sorting specs
  Only sort by IDs by default
  Added benchmark for User.all
  Add changelog entry for contacted_at
  Spread out runner contacted_at updates
  Only redirect to homepage url when its not the root url
  ...

Add Facebook authentication

See merge request !1740

Replace all usages of `git` command with configurable binary path

Closes #3311

See merge request !1742

Only redirect to homepage url when its not the root url

It was possible to create an infi redirect when the user set up the
`home_page_url` to redirect to the main URL of the gitlab instance.

This fix makes sure this redirect is not possible.

Fixes #1020 

/cc @dblessing 

See merge request !1703

Improvements to profile page UI

* add separator between tabs
* show project avatars
* fix tooltip offset on user calendar
* remove gray hover for tabs
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

For #3042

See merge request !1747

* add separator between tabs
* show project avatars
* fix tooltip offset on user calendar
* remove gray hover for tabs
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Improve performance of creating projects



See merge request !1650

Remove duplicate orders

This changes the default order from `created_at DESC, id DESC` to just `id DESC` as this achieves the same results without the overhead of having to sort data twice (we've seen queries go from 200ms to just a few ms by removing the double sort).

cc @jacobvosmaer @dzaporozhets @rspeicher @DouweM 

See merge request !1735

Bump stamp to ~> 0.6.0

Closes #2801

See merge request !1732

Closes #3311

[ci skip]

When project is updated and it is a fork, then visibility_level
should not be less restrictive than in its parent project.

Closes #2801

Spread out runner contacted_at updates

This is meant to prevent having too many concurrent UPDATE requests
caused by runners checking in.

See merge request !1722

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

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

Fix clipboard button overflow
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

See merge request !1739

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

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

Cleanup stuck CI builds

Fixes #3143

/cc @dzaporozhets @jacobvosmaer 

See merge request !1655

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

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

Extend yml syntax for only and except to support specifying repository path

This allows to limit execution of jobs to specific repository.

For example:
```yaml
job:
  only:
    - branches@gitlab-org/gitlab-ce
  except:
    - master@gitlab-org/gitlab-ce
```

The above will run `job` for all branches on `gitlab-org/gitlab-ce`, except master.

@dzaporozhets @JobV @vsizov Please review.


See merge request !1720

Remove inflector rule that makes commits uncountable
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Before: 

```
>> "commits".singularize
=> "commits"
>> "commit".pluralize
=> “commits”
```

After: 

```
>> "commits".singularize
=> "commit"
>> "commit".pluralize
=> “commits”
```

cc @rspeicher 

See merge request !1726

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

The descriptions were not accurate and one particular spec seemingly
expected the wrong User row to be returned.

Sorting by both "created_at" and "id" in descending order is not needed
as simply sorting by "id" in descending order will already sort rows
from new to old. Depending on the query and data involved sorting twice
can also introduce significant overhead.