Merge remote-tracking branch 'origin/develop' into shigusegubu

* origin/develop:
  Apply suggestion to src/components/chat_list/chat_list.vue
  Add the single-line prop to StatusContent and use it for chat list items
  Remove direct style manipulations in favor of classes
  Undo the promise rejection on the json parser error in promisedRequest
  Add the empty chat list placeholder.
  Disable status preview in the chat posting form
  Address feedback
  Add Chats

src/modules/config.js

@@ -46,7 +46,8 @@ export const defaultState = {
     repeats: true,
     moves: true,
     emojiReactions: false,
-    followRequest: true
+    followRequest: true,
+    chatMention: true
   },
   webPushNotifications: false,
   muteWords: [],