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.

spec/fabricators/custom_filter_fabricator.rb

@@ -0,0 +1,6 @@
+Fabricator(:custom_filter) do
+  account
+  expires_at nil
+  phrase     'discourse'
+  context    %w(home notifications)
+end