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

Manually-resolved conflicts:
	.circleci/config.yml
	app/controllers/accounts_controller.rb
	app/controllers/auth/passwords_controller.rb
	app/controllers/statuses_controller.rb
	app/javascript/packs/public.js
	app/models/media_attachment.rb
	app/views/stream_entries/_content_spoiler.html.haml
	app/views/stream_entries/_media.html.haml
	config/locales/en.yml
	config/locales/ja.yml
	config/locales/pl.yml
	lib/mastodon/version.rb

Some content from app/javascript/packs/public.js has been split to
app/javascript/core/settings.js.

Translation strings for glitch-soc's keyword mutes were dropped.

Everything else was mostly “take both”.

app/controllers/auth/registrations_controller.rb

@@ -9,6 +9,7 @@ class Auth::RegistrationsController < Devise::RegistrationsController
   before_action :set_pack
   before_action :set_sessions, only: [:edit, :update]
   before_action :set_instance_presenter, only: [:new, :create, :update]
+  before_action :set_body_classes, only: [:new, :create]
 
   def destroy
     not_found
@@ -84,6 +85,10 @@ class Auth::RegistrationsController < Devise::RegistrationsController
     @instance_presenter = InstancePresenter.new
   end
 
+  def set_body_classes
+    @body_classes = 'lighter'
+  end
+
   def set_invite
     @invite = invite_code.present? ? Invite.find_by(code: invite_code) : nil
   end