- Some views had a "Close" button. We've removed this, because we don't
  want users accidentally hiding the validation errors and not knowing
  what needs to be fixed.
- Some views used `li`, some used `p`, some used `span`. We've
  standardized on `li`.
- Some views only showed the first error. We've standardized on showing
  all of them.
- Some views added an `#error_explanation` div, which we've made
  standard.

I’ve removed everything related to the feature based on this commit:
ce08f919f34fd8849834365

Resolves #10857.

Prevent Groups to have smaller visibility than projects
Add default_group_visibility_level to configuration
Code improvements

Currently any spam detected by Akismet by non-members via API will be logged
in a separate table in the admin page.

Closes #5612

This partially reverts 6a5cd3ca - we keep the migration and add a new
migration that reverts it in order to keep migration history intact.

Introduced by me through !2005

InfluxDB over UDP doesn't use authentication, thus there's no need for
these settings.

[ci skip]

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.

- Offloads uploading to GitLab Workhorse
- Use /authorize request for fast uploading
- Added backup recipes for artifacts
- Support download acceleration using X-Sendfile

This option only existed to ease the CI-to-CE/EE migration process.

This commit partially reverts 8b05abe8

Fixes #2536
Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>

delay is in seconds
more legible code in session_store
Added `GitLab restart required` help block to session_expire_delay

settings