Render HipChat notification descriptions as HTML instead of raw markdown

## What does this MR do?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/1621 for issues, merge requests and comments.

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

This MR is small enough to double check everything.

## Why was this MR needed?

Because seeing raw markdown in HipChat notifications is not nice :)

See merge request !6371

Fix a 500 error viewing an MR with a deleted source project

## What does this MR do?

Allows merged MRs to be shown without any 500 errors if the source project is removed

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

https://gitlab.com/gitlab-org/gitlab-ce/commit/31c37c6c38258684fc92e0d91119c33872e39034 fixed this for closed MRs only. I had trouble understanding the introduced helper and logic, so reverted it and keyed everything on the existence of the source project or branch directly.

commits.json returns a 500 error for a closed or merged MR; the approach taken in the above MR was to hide the commits... tab, so I've run with that.

For merged MRs, the commits (but not the pipeline data) are in the target project, so we *could* do better, but it's a fairly nasty intervention to make it happen.

## Why was this MR needed?

Viewing merged MRs should work even if the fork they came from has been deleted or unlinked.

## Screenshots (if relevant)

![Screen_Shot_2016-10-19_at_17.56.37](/uploads/1aeadd5147b9a4ad29b946b1c7ea52cb/Screen_Shot_2016-10-19_at_17.56.37.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [ ] 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?

Closes #23341

See merge request !6991

Add tooltip with jobs full name to pipelines graph

## What does this MR do?

This MR adds a tooltip to build items in the pipelines graph as some build names are truncated.

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

## Why was this MR needed?

Some job names that are truncated need to be fully identified to avoid confusion.

## Screenshots (if relevant)

[Latest screenies here!](https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6403#note_16968703).

## Does this MR meet the acceptance criteria?

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

## What are the relevant issue numbers?


Closes #22089

See merge request !6403

Change input order on Sign In form for better tabbing.

## What does this MR do?

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

## Screenshots (if relevant)

(Disregard the grey borders on invalid inputs -- for some reason, Gifox isn't picking up some colors for me 🤷 )

![2016-10-17_11.32.05](/uploads/f395b2d77fb47cac3f9d4fa1bc3d7d71/2016-10-17_11.32.05.gif)

## Does this MR meet the acceptance criteria?

- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- Tests
  - [x] 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?
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6867

See merge request !6928

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/...

Restrict ProjectCacheWorker jobs to one per 15 min

## What does this MR do?

This restricts performing ProjectCacheWorker jobs to once every 15 minutes per project. The goal of this is to reduce disk load in the event of a lot of pushes happening in a short period of time. 

The impact is that cached data (e.g. commit count) may be updated less frequently. Furthermore it could mean that separate push payloads won't lead to e.g. READMEs being updated. Most of the cached data isn't updated very frequently, so this trade off should be worth it considering the alternative is a burning storage layer. 

In the future we'll have to flush caches in a smarter way. For example, refreshing the README cache could probably be done separately from the other caches with its own lease and such. See https://gitlab.com/gitlab-org/gitlab-ce/issues/23550 for more information.

See merge request !7017

Removed code from project members controller

## What does this MR do?

Removes code that was meant to be added to a different branch as an experiment.

See merge request !7012

Make label API spec independent of order

See merge request !7013

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).

Create project feature when project is created

closes #22944

See merge request !6908

Refactoring find_commits method

It's possible that `find_commits_by_message` return nil in array which is not OK. We have different checks outside of this method. This MR places all checks inside the method.

See merge request !7000

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

Resolve "Breaking a parameter table in Projects API doc"

## What does this MR do?

- A broken markdown in `Search for projects by name` is fixed.
    - cf. !6681
- Pagination is removed from `Search for projects by name` like other docs as it is shown in [/api/README.html](https://docs.gitlab.com/ce/api/README.html)

## Moving docs to a new location?

No.

## What are the relevant issue numbers?

Closes #23555

See merge request !7007

Differentiate the expire from leave event

At the moment we cannot see whether a user left a project due to their
membership expiring or 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 feasible 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.

Closes #22611 

![Screen_Shot_2016-10-06_at_09.27.52](/uploads/e4de7bd2cdedc64a9b19e56fefa21314/Screen_Shot_2016-10-06_at_09.27.52.png)

See merge request !6717

Fixed height of issue board blank state

## What does this MR do?

The height of the issue board blank state was causing some weird scrolling issues. This MR changes the height of the blank state.

See merge request !6960

Smaller min-width for MR pipeline table

## What does this MR do?
Nests class under `.tab-pane` to make sure buttons don't get cut off

## Screenshots (if relevant)
![Screen_Shot_2016-10-14_at_11.00.02_AM](/uploads/6e19e0375721f2cb58223c2e7ed89308/Screen_Shot_2016-10-14_at_11.00.02_AM.png)

## What are the relevant issue numbers?
Closes #23346

See merge request !6893

This reverts commit 31c37c6c.

See #23341

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

Fix 'No label' and 'Any label' filters

## What does this MR do?

Returns the `title`as the `id` for `No label`.

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

## Why was this MR needed?

Label filters not working as expected

## Screenshots (if relevant)

![2016-10-19_04.58.08](/uploads/3b079bf28299c1155e0243171ac008f6/2016-10-19_04.58.08.gif)

## Does this MR meet the acceptance criteria?

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

## What are the relevant issue numbers?


Closes #23375

See merge request !6974