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

Conflicts:
	README.md
	app/controllers/statuses_controller.rb
	app/lib/feed_manager.rb
	config/navigation.rb
	spec/lib/feed_manager_spec.rb

Conflicts were resolved by taking both versions for each change.
This means the two filter systems (glitch-soc's keyword mutes and tootsuite's
custom filters) are in place, which will be changed in a follow-up commit.

config/application.rb

@@ -42,6 +42,7 @@ module Mastodon
       :bg,
       :ca,
       :co,
+      :da,
       :de,
       :el,
       :eo,