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

Conflicts:
- `Gemfile.lock`:
  Not a real conflict, just a glitch-soc-only dependency too close to a
  dependency that got updated upstream. Updated as well.
- `app/models/status.rb`:
  Not a real conflict, just a change too close to glitch-soc-changed code
  for optionally showing boosts in public timelines.
  Applied upstream changes.
- `app/views/layouts/application.html.haml`:
  Upstream a new, static CSS file, conflict due to glitch-soc's theming
  system, include the file regardless of the theme.
- `config/initializers/content_security_policy.rb`:
  Upstream dropped 'unsafe-inline' from the 'style-src' directive, but
  both files are very different. Removed 'unsafe-inline' as well.

app/models/status.rb

@@ -203,14 +203,6 @@ class Status < ApplicationRecord
     preview_cards.first
   end
 
-  def title
-    if destroyed?
-      "#{account.acct} deleted status"
-    else
-      reblog? ? "#{account.acct} shared a status by #{reblog.account.acct}" : "New status by #{account.acct}"
-    end
-  end
-
   def hidden?
     !distributable?
   end
@@ -342,7 +334,7 @@ class Status < ApplicationRecord
       query = timeline_scope(local_only)
       query = query.without_replies unless Setting.show_replies_in_public_timelines
 
-      apply_timeline_filters(query, account, local_only)
+      apply_timeline_filters(query, account, [:local, true].include?(local_only))
     end
 
     def as_tag_timeline(tag, account = nil, local_only = false)
@@ -434,8 +426,15 @@ class Status < ApplicationRecord
 
     private
 
-    def timeline_scope(local_only = false)
-      starting_scope = local_only ? Status.local : Status
+    def timeline_scope(scope = false)
+      starting_scope = case scope
+                       when :local, true
+                         Status.local
+                       when :remote
+                         Status.remote
+                       else
+                         Status
+                       end
       starting_scope = starting_scope.with_public_visibility
       if Setting.show_reblogs_in_public_timelines
         starting_scope