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

Manually-resolved conflicts:
	.circleci/config.yml
	app/controllers/accounts_controller.rb
	app/controllers/auth/passwords_controller.rb
	app/controllers/statuses_controller.rb
	app/javascript/packs/public.js
	app/models/media_attachment.rb
	app/views/stream_entries/_content_spoiler.html.haml
	app/views/stream_entries/_media.html.haml
	config/locales/en.yml
	config/locales/ja.yml
	config/locales/pl.yml
	lib/mastodon/version.rb

Some content from app/javascript/packs/public.js has been split to
app/javascript/core/settings.js.

Translation strings for glitch-soc's keyword mutes were dropped.

Everything else was mostly “take both”.

app/javascript/core/public.js

@@ -1,6 +1,7 @@
 //  This file will be loaded on public pages, regardless of theme.
 
 const { delegate } = require('rails-ujs');
+const { length } = require('stringz');
 
 delegate(document, '.webapp-btn', 'click', ({ target, button }) => {
   if (button !== 0) {