Refactor the spec file:
- remove hardcoded record IDs
- avoid top-level let if not used in all scenarios
- prefer expect { ... }.to change { ... }.from(0).to(1) over checking
that there are no records at the beginning of the test

This patch makes sure GitLab does not save the refs to the filesystem
each time the deployment is updated. This will save some IO although I
expect the impact to be minimal.

Closes #23208

The `class` and `data-*` attributes are meaningless in HipChat, and it
would probably be better to limit the tags, too. For example, we could
avoid block-level elements in `render_line`.

"pipeline: :single_line" leaves the protocol/host part out of the URLs
and caches them that way. To avoid giving those out to HipChat, markdown
is always rendered with "pipeline: :email" first.

There must be a better way to do this, but I can't see how to avoid the
link caching.

Using "pipeline: :email" gets "only_path: false" into the context to
produce full URLs instead of /namespace/project/...

This reverts commit 31c37c6c.

See #23341

Added tooltips for dropdown items

Reverted pretty much everything in favour of a DOM approach

Simplified JS

Added status to build tooltip and removed status icon tooltip

Added Pipelines class to force tooltips ontop of the dropdown, we cannot do this with data attributes because dropdown toggle is already set

Corrected dispatcher invocation

This *unreverts* 8751491b, which was mistakenly
reverted in !6328. It also changes the implementation of the
original commit to work with the new login styling and
markup.

cc: @ClemMakesApps

This ensures ProjectCacheWorker jobs for a given project are performed
at most once per 15 minutes. This should reduce disk load a bit in cases
where there are multiple pushes happening (which should schedule
multiple ProjectCacheWorker jobs).

This code was meant to be added to another branch as an expirement, but instead was commited to wrong branch

At the moment we cannot see weather a user left a project due to their
membership expiring of if they themselves opted to leave the project.
This adds a new event type that allows us to make this differentiation.
Note that is not really feasable to go back and reliably fix up the
previous events. As a result the events for previous expire removals
will remain the same however events of this nature going forward will be
correctly represented.

Set webkit-overflow-scrolling to auto for children of body.

## What does this MR do?

Fixes weird tooltip layering behavior in iOS Safari. See screenshots and/or the original issue: https://gitlab.com/gitlab-org/gitlab-ce/issues/22816

## Why was this MR needed?

Tooltips were cutoff in Safari.

## Screenshots (if relevant)

Before: 
![Screen_Shot_2016-10-18_at_7.13.11_PM](/uploads/5558d60b7369a9355f18d34dcc2c179e/Screen_Shot_2016-10-18_at_7.13.11_PM.png)


After:
![Screen_Shot_2016-10-18_at_7.13.40_PM](/uploads/ae07002f2f396f135b3078538d5c4ad6/Screen_Shot_2016-10-18_at_7.13.40_PM.png)

Also, as part of this fix, I removed applications of `-webkit-overflow-scrolling: auto` in two other places where they're no longer needed. One was the file-holder. I made sure I could reproduce the behavior this was intended to fix, and then made sure this MR still fixed it. 

Here's the errant behavior: 

![2016-10-18_19.00.22](/uploads/0bd3ee3bab44769dfce80c7edaac3248/2016-10-18_19.00.22.gif)

Here's what it looks like with this MR:

![2016-10-18_19.00.49](/uploads/e405ded5acdbbbe5e577222c11198691/2016-10-18_19.00.49.gif)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
 - [ ] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

See merge request !6962