Make diff file view easier to use on mobile screens

Viewing diffs on a mobile screen is a bit of an awkward experience at the moment. Here are a few issues (by no means complete):

## Before

### Tabs are scrunched

![image](https://gitlab.com/stanhu/gitlab-ce/uploads/45924e36cfb107dc56795a7dcdfbc5b5/image.png)

### Filenames take too much room, buttons cluttered

![image](https://gitlab.com/stanhu/gitlab-ce/uploads/a5e5611271fe26dfd3922aa0b8780458/image.png)

## After

This MR makes a few tweaks to make this a bit better. It just addresses a few issues, but there is plenty of room for improvement (e.g. shrink fonts, etc.):

### Eliminate padding to make tabs fit

![image](https://gitlab.com/gitlab-org/gitlab-ce/uploads/fbcf128d1f221b9b9e53df274238dc62/image.png)

### Make filenames, buttons more readable

This screenshot allows the filename to use the whole row, omits the file mode changes, and puts the buttons centered in the view:

![image](https://gitlab.com/gitlab-org/gitlab-ce/uploads/d2e5b9424f058827ba2552056c516e18/image.png)

Towards a better mobile experience: #2787 

See merge request !1449

Remove whenever gem

Closes #2879 

See merge request !1538

[ci skip]

Update CHANGELOG for Emoji fix in a3c6ed5c

[ci skip]

See merge request !1556

[ci skip]

Restore placeholders in issue filters from "Any" to "Milestone" and "Label"

1f11096c included new filters but made it hard to determine which dropdown did
what. This patch restores the original placeholders.

### Before

![image](https://gitlab.com/stanhu/gitlab-ce/uploads/2326b836e364275341ea0ad8c0a0926b/image.png)

### After

![image](https://gitlab.com/stanhu/gitlab-ce/uploads/b0e519f9cf8d1a3c0f054286e3b809cb/image.png)


See merge request !1554

Normalize space-like characters in keys before output to gitlab-shell

gitlab-shell expects only one tab separator per key, and an SSH key with
a tab character in the comment, for example, would break things.

Closes #2970

See merge request !1552

Make the loading spinner toggle more explicit

Occasionally the loading spinner would stay visible after the tab
finished loading. This change makes the toggle explicit so that it's
always shown on `beforeSend`, and always hidden on `complete`.

Plus a bonus semi-colon eradication! 💥

See merge request !1553

Clarify support request message

Since we have the (GitLab.com) Support Forum, this message may be slightly confusing. Hopefully this wording improves understanding. If anyone has suggestions on making this clearer I'm open.

See merge request !1406

Add task to disable 2FA for all users

Addresses #2971 

See merge request !1532

Show message if user tries to fork and has no available namespaces

This merge request improves the UX when users try to fork a project and have no eligible namespaces. 

### Current behavior

![Screen_Shot_2015-09-25_at_1.39.45_PM](https://gitlab.com/dblessing/gitlab-ce/uploads/45a303703a0197e78f7f9bdbea8718b5/Screen_Shot_2015-09-25_at_1.39.45_PM.png)

### Proposed behavior

![Screen_Shot_2015-09-25_at_1.38.57_PM](https://gitlab.com/dblessing/gitlab-ce/uploads/613c53bcfb52d79fdf8bd1d09410c152/Screen_Shot_2015-09-25_at_1.38.57_PM.png)

### Things to check

I'm not exactly loving the wording I have here. I'm open to improvements.


See merge request !1441

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

1f11096c included new filters but made it hard to determine which dropdown did
what. This patch restores the original placeholders.

 - 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

Occasionally the loading spinner would stay visible after the tab
finished loading. This change makes the toggle explicit so that it's
always shown on `beforeSend`, and always hidden on `complete`.

Plus a bonus semi-colon eradication! 💥

gitlab-shell expects only one tab separator per key, and an SSH key with
a tab character in the comment, for example, would break things.

Closes #2970

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