Removable labels from filtered issuables label bar

When filtering by labels, a remove button appears next to each label. This then removes that label & refreshes the issuable filter form

![Screen_Shot_2016-05-17_at_12.07.47](/uploads/b21e86247aa1bbfd347bef1eb21f1562/Screen_Shot_2016-05-17_at_12.07.47.png)

Closes #15474

See merge request !4178

Backported from EE shared form for web hooks

## What does this MR do?

EE uses a shared form for web hooks - so this brings that across to CE.

See merge request !4457

Add fog-azure to supported backup list

!4396 left out Azure by accident.


See merge request !4444

Dismantling Grack::Auth part 1: Git HTTP clients

Part of https://gitlab.com/gitlab-org/gitlab-ce/issues/14501

This does not completely get rid of Grack::Auth yet because Git LFS
support is 'behind' it and I would like to not make this MR bigger
than needed.

- changed tests to make HTTP requests instead of calling Rack apps
- added missing test cases for Git HTTP authentication
- moved Git HTTP requests into a 'normal' Rails controller

See merge request !3361

Fix endless redirections when accessing user OAuth applications when they are disabled

## What does this MR do?

This MR fixes a bug where the browser would be redirect endlessly when attempting to access the user's OAuth applications when an admin has disabled this system-wide setting.

## Are there points in the code the reviewer needs to double check?

I assume disabling the nav button is better than showing a page that says, "OAuth applications are disabled by the admin."

## Why was this MR needed?

Lots of users were confused when they hit endless redirect errors.

## What are the relevant issue numbers?

#14770 

See merge request !4525

Fix markdown_spec to not use `before(:all)` in order to properly cleanup database after testing



See merge request !4515