Spinach fix

/cc @rspeicher @rdavila 

See merge request !2263

See merge request !2262

See merge request !2252

While it's useful to keep track of the different versions (Ruby, GitLab,
etc) doing so for every point wastes disk space and possibly also RAM
(which InfluxDB is all to eager to gobble up). If we want to see the
performance differences between different GitLab versions simply looking
at the performance since the last release date should suffice.

Swap Author and Assignee Selectors on issuable index view

Closes #4039

See merge request !2256

[ci skip]

Why did this break? `¯\_(ツ)_/¯`

Closes #4039

Remove unused config/schedule.rb file

[ci skip]

See merge request !2249

[ci skip]

Ensure that is no pending migrations when using database on
Gitlab::CurrentSettings

This fixes the undefined method `recaptcha_enabled' for
#<ApplicationSetting:0x007f28552f8238> when running the build.

See merge request !2254

Added additional config environmental variables to help Debian packaging

* GITLAB_EMAIL_FROM
* GITLAB_EMAIL_DISPLAY_NAME
* GITLAB_EMAIL_REPLY_TO

This is a followup on https://gitlab.com/gitlab-org/gitlab-ce/issues/3717

See merge request !2251

* GITLAB_EMAIL_FROM
* GITLAB_EMAIL_DISPLAY_NAME
* GITLAB_EMAIL_REPLY_TO

**Why is this needed?**

Not really needed, but having code that is not used around is confusing, so lets
remove it
Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>

Hotfix for builds trace data integrity

Closes #4246

See merge request !2224

Fixes problem with user autocomplete URI 

```
Failed to load resource: net::ERR_NAME_NOT_RESOLVED
http://autocomplete/users.json?search=&per_page=20&active=true&current_user=false
```

Fixes #4118, #4136

See merge request !2136

Fix project transfer e-mail sending incorrect paths in e-mail notification

The introduction of ActiveJob and `deliver_now` in 7f214cee caused a race
condition where the mailer would be invoked before the project was committed
to the database, causing the transfer e-mail notification to show the old
path instead of the new one.

Closes #4670

See merge request !2235

The introduction of ActiveJob and `deliver_now` in 7f214cee caused a race
condition where the mailer would be invoked before the project was committed
to the database, causing the transfer e-mail notification to show the old
path instead of the new one.

Closes #4670

[ci skip]

Revert upvotes and downvotes params back to MR API

issue https://gitlab.com/gitlab-org/gitlab-ce/issues/3672

See merge request !2212

See merge request !2239

This ensures we can still start up even when not connecting to a
database.

See merge request !2238

This removes the need for Sidekiq and any overhead/problems introduced
by TCP. There are a few things to take into account:

1. When writing data to InfluxDB you may still get an error if the
   server becomes unavailable during the write. Because of this we're
   catching all exceptions and just ignore them (for now).
2. Writing via UDP apparently requires the timestamp to be in
   nanoseconds. Without this data either isn't written properly.
3. Due to the restrictions on UDP buffer sizes we're writing metrics one
   by one, instead of writing all of them at once.