Fixed positioning of hamburger menu on header

Hey guys just noticed the hamburger menu for the top navigation was mis-aligned on 
`gitlab-ce:master` and `gitlab.com`.
I was not able to find an open issue or merge request directly referencing this issue so thought I would add a quick fix.

### Changes

This MR changes the vertical positioning from `top` to vertical margins (Like in bootstrap itself).
 - Also added a minor fix to remove `border-top` from the collapse menu so its the same height as the navigation.
 - finally added an active class to the hamburger toggle so you can see when its open.

This changes an element in `app/views/layouts/header/_default.html.haml` and thus would impact most pages behind login.

## Screenshots

### Before

![before](https://gitlab.com/hanloong/gitlab-ce/uploads/e3d4631dd0420ec0e9048c435a2f734b/before.png)

### After

![after](https://gitlab.com/hanloong/gitlab-ce/uploads/7c93c3ef1b01fbefc39c5a1ed61c2d1b/after.png)

Happy to discuss any changes/suggestions.

Thanks

See merge request !1541

 - Changed to margin for vertical allign as used in bootstrap 3 original
 - Also added an `active` state to show when the extra items are enabled

allow crawling of commit page but not patch/diffs

Fixes GDK issue where repos would not be imported properly

Seed-Fu runs this entire fixture in a transaction, so the `after_commit`
hook won't run until after the fixture is loaded. That is too late
since the Sidekiq::Testing block has already exited. Force clearing
the `after_commit` queue to ensure the job is run now.

See: gitlab-org/gitlab-development-kit#58

See merge request !1513

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

Update upgrade guide for Redis >= 2.4.0 requirement

[ci skip]

Closes #2837

See merge request !1468

Add new GitLab colors

After this merge request all css must use variables for colours.

![7Od6vP7usJ__1_](https://gitlab.com/gitlab-org/gitlab-ce/uploads/01dd327770f25c76448a5860a76e34c9/7Od6vP7usJ__1_.png)
 
cc @skyruler 

See merge request !1542

This ensures any PostgreSQL specific schema changes (e.g. expression
indexes) are created when setting up the database.

By using a JOIN we can remove the need for using 2 separate queries to
find a project by its namespace. Combined with an index (only needed for
PostgreSQL) this reduces the query time from ~245 ms (~520 ms for the
first call) down to roughly 10 ms (~15 ms for the first call).

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

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

Update slack-notifier to ~> 1.2.0

Closes #2826 

See merge request !1533

Update tinder to ~> 1.10.0

Closes #2823 

See merge request !1534

Update rack-cors to ~> 0.4.0

Closes #2800 

See merge request !1536

Update haml-rails to ~> 0.9.0

Closes #2804 

See merge request !1535

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

cc @ayufan 

See merge request !1539

Add "Quick Submit" JS behavior

This takes the "Command+Enter" (or "Ctrl+Enter") quick-post behavior from the discussion field and expands it to fields throughout the application, most notably the issuable forms (e.g., New Issue, Edit Merge Request).

See merge request !1516

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

This was added in rack-cors 0.4.0 and allows all types of CORS requests
to the API.

phantomjs < 2.0 doesn't support creating `KeyboardEvent` so the tests
were failing on CI

On PostgreSQL these queries use LOWER(...) to compare columns and
values. For MySQL a regular WHERE is performed as MySQL is already
case-insensitive.

These two methods remove the need for manually going into
ActiveRecord::Base.connection all over the place.

Clarify Reply by email settings when using Postfix mail server

Fixes #2902.

[ci skip]

See merge request !1528

[ci skip]

Adds quick submit behavior to the forms for:

- Blobs ("new file")
- Commit messages
- Issuables
- Notes
- Labels
- Milestones
- Wikis

Side-effect: This simplifies the requiresInput handler

Update omniauth-* gem dependencies

- twitter to `~> 1.2.0` - closes #2763
- kerberos to `~> 0.3.0` - closes #2792
- google-oauth2 to `~> 0.2.0`
- shibboleth to `~> 1.2.0` - closes #2791

See merge request !1526