Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- Gemfile
- app/controllers/api/v1/search_controller.rb
  Conflict because we changed the number of default results to be
  configurable
- app/lib/settings/scoped_settings.rb
  Addition of a new “noindex” site-wide setting,
  conflict due to our change of the two other site-wide settings
  (default flavour and skin instead of theme)
- spec/controllers/application_controller_spec.rb
  Addition of a new “noindex” site-wide setting,
  conflict due to our change of the two other site-wide settings
  (default flavour and skin instead of theme)

spec/fabricators/marker_fabricator.rb

@@ -0,0 +1,6 @@
+Fabricator(:marker) do
+  user
+  timeline     'home'
+  last_read_id 0
+  lock_version 0
+end