Inline diff is going to be generated client side now. #3945

Now we apply syntax highlighting to the whole old and new files.
This basically help us to highlight adequately multiline content.

* It is more performant given now we process all the diff file instead
  of processing line by line.
* Multiline comments are highlighted correctly.

Handle missing settings table for metrics



See merge request !2232

Fix broken link in permissions page



See merge request !2233

This ensures we can still boot, even when the "application_settings"
table doesn't exist.

Move InfluxDB settings to ApplicationSetting

This moves the settings from the YAML files to the database.

cc @sytses

See merge request !2228

Fixed syntax in gitlab.yml.example



See merge request !2230

Restart settings are moved too.



See merge request !2226