Pass `updated_at` to get only incremental changes since last update

Refine CI Statuses

## What does this MR do?

This MR introduces classes for each relevant CI status.

## What are the relevant issue numbers?

Closes #24273

See merge request !7889

Use `--extended-regexp` in lint-doc for compatibility with Darwin grep

Now it should work on all platforms.

See merge request !7943

GLM shorthand reference for projects from the same namespace

Closes #21679

See merge request !7255

Authorize users into imported GitLab project

https://gitlab.com/gitlab-com/support-forum/issues/1313

See merge request !7936

Fixed MR widget content wrapping for XS viewports

Centers the "Accept Merge Request" button within the MR widget (and adds a bit of right/left padding) for viewports smaller than 768px.

BEFORE:
![Screen_Shot_2016-12-02_at_8_53_01_AM](/uploads/fcdae5302a1407090483dd3cff868c51/Screen_Shot_2016-12-02_at_8_53_01_AM.png)

AFTER:
![Screen_Shot_2016-12-02_at_9_43_37_AM](/uploads/f7d1dce082b79d263f05cea3c90e870a/Screen_Shot_2016-12-02_at_9_43_37_AM.png)

cc: @markglenfletcher @annabeldunstone 
Closes #25202

See merge request !7900

Ensure state param has a valid value when filtering issuables.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/25064

This fix makes sure we only call safe methods on issuable when filtering by state.

See merge request !2038

Document the public Project API and document `GET /projects/:id/users`

Documentation was not updated in !7843. Also the `GET /projects/:id/users` endpoint was not documented at all!

See merge request !7897

Remove unused errors css

`.error-page` isn't being used anywhere as far as I can see so I removed it

See merge request !7933

Remove unused votes.scss

`.votes-inline` isn't being used anywhere

See merge request !7934

NIGNX -> Nginx

This shouldn't be in all caps, and it should be spelled correctly!

See merge request !7929

It's secret variables, not secure

See merge request !7939

[ci skip]

Refactor CI variables docs

See merge request !7751