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

Conflicts:
	app/controllers/accounts_controller.rb
	app/javascript/mastodon/locales/pl.json
	app/views/about/more.html.haml

Conflicts in `accounts_controller.rb` resolved by taking upstream's
version + our `use_pack`.

Conflicts in `pl.json` resolved by taking upstream's changes.

Conflicts in `aboute/more.html.haml` resolved by taking upstream's changes.

config/routes.rb

@@ -321,6 +321,9 @@ Rails.application.routes.draw do
           post :mute
           post :unmute
         end
+
+        resource :pin, only: :create, controller: 'accounts/pins'
+        post :unpin, to: 'accounts/pins#destroy'
       end
 
       resources :lists, only: [:index, :create, :show, :update, :destroy] do