Merge remote-tracking branch 'origin/master' into gs-master

Conflicts:
 	app/controllers/home_controller.rb
 	app/controllers/stream_entries_controller.rb
 	app/javascript/mastodon/locales/ja.json
 	app/javascript/mastodon/locales/pl.json

package.json

@@ -84,8 +84,8 @@
     "prop-types": "^15.5.10",
     "punycode": "^2.1.0",
     "rails-ujs": "^5.1.2",
-    "react": "^16.2.0",
-    "react-dom": "^16.2.0",
+    "react": "^16.3.0",
+    "react-dom": "^16.3.0",
     "react-hotkeys": "^0.10.0",
     "react-immutable-proptypes": "^2.1.0",
     "react-immutable-pure-component": "^1.1.1",