Resolve ""When this merge request is accepted, this issue will be closed automatically" rendered twice"
## What does this MR do?
1. Only show the above text when there is an MR that will close the issue, and even then, only show it once.
2. Apply 98f147e84d2bd8f2278452ac0852118452c76d4a to a bunch of other places that need it.
## Are there points in the code the reviewer needs to double check?
¯\_(ツ)_/¯
## Why was this MR needed?
Some pages were broken.
## What are the relevant issue numbers?
Fixes#18446.
## Screenshots (if relevant)
Before:

After:

## 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 [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)
See merge request !4594
#17562 Fixes issues list filter only visible when user is logged in
## What does this MR do?
1. Moves the issue/MR list search form out of the `if current_user` conditional, allowing guests to view the field.
2. Adds some margin to the search form, this is because in mobile view for guest users, the field was not supported by the RSS button and the New Issue button and would drop to meet the list.
## Are there points in the code the reviewer needs to double check?
Are there any views where the `margin-bottom: 12px` will affect the styling?
## Why was this MR needed?
Guest user UX. Nothing feels better than increasing intangible value!
## What are the relevant issue numbers?
Fixes#17562.
## Screenshots (if relevant)

/cc @jschatz1
**UPDATE:**

See merge request !4171
Fixes the bottom margin of .nav-controls > form (issues list search/filter form) so when a guest views on the field on mobile it is not squished against the issues list
Updated CHANGELOG
navigation tabs and navigation filter search will now stay on the same row until there is no space to
Removed unneeded media queries
Separate reference gathering from rendering
This is a required step to allow batch processing when gathering references. This in turn would allow grabbing (for example) all mentioned users of an issue/merge request using a single query.
cc @rspeicher @DouweM
See merge request !3969
Replace `link_to_gfm` with `link_to` in merge request and issue titles.
## What does this MR do?
This removed GitLab Markdown Formatting from issue titles due to issues and confusion it caused as well as performance reasons.
On the issue/MR page itself, the formatting is preserved. This only effects index pages. See:

I think the trade-off here is worth it, otherwise we'd just be playing wack-a-mole.
## Are there points in the code the reviewer needs to double check?
I don't think so.
## Why was this MR needed?
Previously if an issue had an emoji for its name it would be unclickable. Similarly, links were rendered inline if the title was something like “Fixes a bug with https://google.com”. This confused a number of users, so it’s removed.
This is also ever so slightly more performant :)
## What are the relevant issue numbers?
This fixes#17614 and #17230.
## Screenshots (if relevant)
Before:

After:

Before:

After:

cc: @rspeicher @jschatz1
See merge request !4284
Previously if an issue had an emoji for its name it would be unclickable. Similarly, links were rendered inline if the title was something like “Fixes a bug with https://google.com”. This confused some users, so it’s removed.
On the issue/MR page itself, the formatting is preserved. This only effects index pages.
This is also ever so slightly more performant :)
This fixes#17614 and #17230.
This button depends on Issue#can_be_worked_on? which in turn depends on
Issue#related_branches. By rendering this button asynchronously we can
finally remove all usages of Issue#related_branches and
Issue#referenced_merge_requests from the issues "show" page.
Ci::Commit becomes a Pipeline object
1. Ci::Commit receives context: ref, :tag.
1. One Ci::Commit describes a one Pipeline
1. Pipeline is created from `.gitlab-ci.yml`
1. Pipeline is a ordered group of builds
1. We test MR against Pipeline
1. Pipelines have a separate view (https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3703)
1. Pipeline can be triggered from UI (https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/3703)
1. Later we change `Trigger -> TriggerRequest -> Build` to `Trigger -> Pipeline` (future)
1. We add a Pipeline Hook that will be triggered on Pipeline status change (future)
1. We extend notifications to use `Pipeline Hook` to send summary on pipeline changes (future)
After merging that I'll prepare a separate MR that will unify naming, database columns, table names:
```
Ci::Commit -> Pipeline
Ci::Build -> Build
CommitStatus -> Job
GenericCommitStatus -> ExternalJob
ci_commits -> pipelines
ci_builds -> jobs
```
This MR implements first 5 points.
This is made to solve this issue https://gitlab.com/gitlab-org/gitlab-ce/issues/14149.
See merge request !3653
Add due_date text field to sidebar issue#show
Add ability sorting issues by due date ASC and DESC
Add ability to filtering issues by No Due Date, Any Due Date, Due to tomorrow, Due in this week options
Add handling issue due_date field for MergeRequest
Update CHANGELOG
Fix ambigous match for issues#show sidebar
Fix SCREAMING_SNAKE_CASE offenses for due date contants
Add specs for due date sorting and filtering on issues