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

Conflicts:
- app/models/media_attachment.rb
  Upstream added audio attachment support
- app/serializers/initial_state_serializer.rb
  Upstream added audio attachment support and how mimetypes are returned
- app/serializers/rest/instance_serializer.rb
  Upstream added a few fields
- config/application.rb
  Upstream added a different paperclip transcoder

app/serializers/rest/instance_serializer.rb

@@ -3,9 +3,9 @@
 class REST::InstanceSerializer < ActiveModel::Serializer
   include RoutingHelper
 
-  attributes :uri, :title, :description, :email,
+  attributes :uri, :title, :short_description, :description, :email,
              :version, :urls, :stats, :thumbnail, :max_toot_chars, :poll_limits,
-             :languages, :registrations
+             :languages, :registrations, :approval_required
 
   has_one :contact_account, serializer: REST::AccountSerializer
 
@@ -19,6 +19,10 @@ class REST::InstanceSerializer < ActiveModel::Serializer
     Setting.site_title
   end
 
+  def short_description
+    Setting.site_short_description
+  end
+
   def description
     Setting.site_description
   end
@@ -68,6 +72,10 @@ class REST::InstanceSerializer < ActiveModel::Serializer
     Setting.registrations_mode != 'none' && !Rails.configuration.x.single_user_mode
   end
 
+  def approval_required
+    Setting.registrations_mode == 'approved'
+  end
+
   private
 
   def instance_presenter