!4318 broke the gitlab:db:drop_tables functionality for PostgreSQL.

Closes #15259

Checks for undefined when inserting autocomplete into textarea

## What does this MR do?

Correctly checks for undefined before inserting anything into the textarea when using autocomplete. This happens because the loading indicator tries to insert `@undefined` which we dont want to insert.

See merge request !4561

Fix bug with SQL syntax error during backup restoration

## What does this MR do?
It properly escapes the table name in the `DROP TABLE IF EXISTS ...` statement used during restore of a backup.

## Are there points in the code the reviewer needs to double check?
Please check compatibility with PostgreSQL

## Why was this MR needed?
Fix an issue with backups can not be restored if MySQL is used as database for GitLab.

## What are the relevant issue numbers?
#15259 

## Screenshots (if relevant)
-

See merge request !4318

Fix empty user projects snippets list

## What are the relevant issue numbers?
Closes #17952 #17816 and  #17737 

cc: @lbennett  @jschatz1 

See merge request !4532

Improve ui consistency. Part 2

* Use responsive top-area on project branches and tags pages
* Use default button size in the content list controls
* Improve button margin for btn-grouped css class

For https://gitlab.com/gitlab-org/gitlab-ce/issues/18324

See merge request !4536

Improved the UX of issue & milestone date picker

## What does this MR do?

Improves the UX of the date picker on issue form & milestone form.

## What are the relevant issue numbers?

Closes #18198 

## Screenshots (if relevant)

### Issues

![Screen_Shot_2016-06-06_at_09.28.29](/uploads/d9c192dff0d8076adc3ed6f005ea3790/Screen_Shot_2016-06-06_at_09.28.29.png)

### Project milestones

![Screen_Shot_2016-06-06_at_09.28.18](/uploads/2d03d72791c5fc6badfadb975a85af2b/Screen_Shot_2016-06-06_at_09.28.18.png)

### Group milestones

![Screen_Shot_2016-06-06_at_09.28.05](/uploads/0f28532396a16e6fd48ddea784ca28e3/Screen_Shot_2016-06-06_at_09.28.05.png)

See merge request !4485

Only load Chart.js when necessary.

Only load Chart.js where it's used, namely the Graphs section. Follow up on !4394.

cc: @jschatz1 

See merge request !4516

Fix local timeago on user dashboard

## What does this MR do?
Fixes incorrect date times on tooltips on the dashboard page

## Are there points in the code the reviewer needs to double check?
Yes,  The tooltip has to be recreated again because we needed a custom CSS classname in order to fix the date being splitted into two lines.

## Why was this MR needed?
Because the datetimes were incorrect we have to have the same format for .timeago() instances.

## What are the relevant issue numbers?
#17607

## Screenshots (if relevant)

**Before**

<img src="/uploads/f40cd58e8086d9675262e98a1fe57885/Screen_Shot_2016-05-24_at_7.23.25_PM.png" width="705">

**After**

<img src="/uploads/bd48046ef11659cc742f827b3404fbcd/Screen_Shot_2016-05-24_at_7.22.29_PM.png" width="704">


See merge request !4285

Improve input padding, fix #18237.

## What does this MR do?
Improves horizontal padding for input fields.

## What are the relevant issue numbers?
#18237

## Screenshots (if relevant)

Before:

![Screen_Shot_2016-06-06_at_12.11.07_PM](/uploads/11d24c84e1ca8d268a5acc2b4e10bb77/Screen_Shot_2016-06-06_at_12.11.07_PM.png)

After:

![Screen_Shot_2016-06-06_at_12.10.38_PM](/uploads/cbb407d8fca1e8dc1ace2af6c0774181/Screen_Shot_2016-06-06_at_12.10.38_PM.png)

cc: @jschatz1 

See merge request !4489

Use warning color merge conflicts icon in MR status widget.

Fixes #18174 

### Before
![Screen_Shot_2016-06-06_at_18.00.56](/uploads/4a74b1710478daee5ee95b7c6b6a835f/Screen_Shot_2016-06-06_at_18.00.56.png)

### After
![Screen_Shot_2016-06-06_at_17.58.04](/uploads/28faefaebef30e4256390029c87b28bb/Screen_Shot_2016-06-06_at_17.58.04.png)

See merge request !4487

Closes #18198

Edit form background color on highlighted note

## What does this MR do?

Added white background to edit form when in a highlighted note

## What are the relevant issue numbers?

Closes #18101 

## Screenshots (if relevant)

![Screen_Shot_2016-06-02_at_11.24.20](/uploads/c7c7fe710aa74d86152a109560fd0ebe/Screen_Shot_2016-06-02_at_11.24.20.png)

See merge request !4435

Toggling a task in a description with mentions doesn't creates a Todo

When user toggle a task list item in a description with a mention it
does not create an unnecessary Todo for that mention.

Closes #14116

See merge request !4568

Blur button tags when pressed to remove the focus state.

## Before 

![pemnD5exKl](/uploads/333155bf4a6c43715f3fc04d8f5aa35e/pemnD5exKl.gif)


## After

![dCPvSwsuWp](/uploads/9bcfbe59ac8de51e9d2c3edcb3d13ff3/dCPvSwsuWp.gif)

See merge request !4418

Updated labels UI

- Fixed alignment issues
- Added dropdown to mobile to make the options look nicer & to save space

![Screen_Shot_2016-05-25_at_09.42.46](/uploads/ff59abd2310725965b388a62c6c1f2af/Screen_Shot_2016-05-25_at_09.42.46.png)

Closes #14227

See merge request !4273

#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)

![Screen_Shot_2016-05-16_at_23.48.06](/uploads/cf0f0c48287517ac3e83b204b4ee09b2/Screen_Shot_2016-05-16_at_23.48.06.png)

/cc @jschatz1 

**UPDATE:**

![Screen_Shot_2016-05-20_at_16.13.22](/uploads/eb854838a514d0d54d0f13bde1636b8a/Screen_Shot_2016-05-20_at_16.13.22.png)

See merge request !4171

Fix 2FA-based login for LDAP users

The OTP input form is shared by both LDAP and standard logins, but when
coming from an LDAP-based form, the form parameters aren't nested in a
Hash based on the `resource_name` value.

Now we check for a nested `remember_me` parameter and use that if it
exists, or fall back to the non-nested parameters if it doesn't.

Somewhat confusingly, the OTP input form _does_ nest parameters under
the `resource_name`, regardless of what type of login we're coming from,
so that allows everything else to work as normal.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/18185

See merge request !4493

Update CHANGELOG

Fixes wrong changelog entry for !4175

See merge request !4548

Closes #14227

Ensure only IDs ending in .git perform git actions

## What does this MR do?

Rails's routing is pretty strange. Previously, `GET /namespace/project/info/refs` would go to the Git HTTP controller (if the redirect for that case was taken out).

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

The specs fail if the redirect is moved to above the Git HTTP routes, removed altogether, or the Git HTTP constraints are changed. But there might still be missing cases.

## Why was this MR needed?

The master build and HTTP cloning were both broken.

## What are the relevant issue numbers?

Closes #18376.

## Screenshots (if relevant)

Nope.

## Does this MR meet the acceptance criteria?

- [x] [not needed] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [not needed] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] (not needed) API support added
- [ ] Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] 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 !4558

It doesn't seem possible to set constraints based on format for project
IDs ending in .git, so set the constraint on the ID and ensure the
format is nil to avoid the case where the project ID is something like
project.git.foo.

Adjust the SAML control flow to allow LDAP identities to be added to an existing SAML user.

## What does this MR do?

It correctly lets an existing SAML user to add their LDAP identity automatically at login.

## Why was this MR needed?

A customer had issues with the `auto_link_ldap_user` feature. The flow was not working if there was an account with a SAML identity, but no LDAP identity. GitLab would pick up the correct LDAP person, but due to the order of the flow, that LDAP person was never associated with the user.

## What are the relevant issue numbers?

Fixes #17346 

/cc @dblessing @balameb @stanhu 

See merge request !4498

Make Omniauth providers specs to not modify global configuration

See merge request !4534

Fix wiki linking behavior for markdown wiki pages

Related to #18019 

- As per the documentation in !4372 

## TODO
- [ ] !4432 Have wiki linking behave as per the documentation
    - [x] Move `WikiLinkFilter` specs to the pipeline level
    - [x] Verify current behavior on wiki `show` page
    - [x] Fix current behavior on wiki `show` page
    - [x] Verify current behaviour on wiki preview
    - [x] Fix current behaviour on wiki preview
        - [x] Rewrite all links and get preview links working
        - [x] Make sure all links are on-par with the wiki `show` page
        - [x] TDD `WikiLinkFilter` and get it working
        - [x] Hook `WikiLinkFilter` up
    - [x] Fix tests 
        - [x] Fix `markdown_spec`
        - [x] Fix `wiki` spinach feature
        - [x] Wait for [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/4f50dd2/builds) to pass
        - [x] Make sure all wiki-related pages are working as expected (history, all pages, etc.)
    - [x] Test in different ruby versions
    - [x] GitLab instances hosted on a relative URL
    - [x] Non-markdown rendering formats?
        - [x] RDoc
        - [x] ASCIIDoc
        - [x] Create issues to fix things for RDoc and ASCIIDoc
    - [x] Gauge performance impact
    - [x] Refactor
    - [x] Re-organize commits
    - [x] Make sure [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/f860e9a8dcabe7d5f160c32fc549807c98baa4a1/builds) passes
    - [x] Respond to @rymai's comments
        - [x] `class WikiLinkFilter < HTML::Pipeline::Filter`
        - [x] blank line after guard clause
        - [x] keyword arguments for `wiki` and `slug`
        - [x] invert the condition
        - [x] inline `user` in spec
        - [x] Make sure spec names are not out of date
        - [x] Comment for each rewrite rule
    - [x] Add CHANGELOG entry
    - [x] Reorganize commits
    - [x] Make sure [build](https://gitlab.com/gitlab-org/gitlab-ce/commit/19b91e749a6320d12fb299d33f1f6440777e0e26/builds) passes
    - [ ] Wait for merge

See merge request !4432