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

Conflicts:
- app/controllers/statuses_controller.rb
  minor conflict because of glitch-soc's theming system
- app/controllers/stream_entries_controller.rb
  minor conflict because of glitch-soc's theming system

db/migrate/20190509164208_add_by_moderator_to_tombstone.rb

@@ -0,0 +1,5 @@
+class AddByModeratorToTombstone < ActiveRecord::Migration[5.2]
+  def change
+    add_column :tombstones, :by_moderator, :boolean
+  end
+end