Fix handleClientMessage_USER_* payloads not containing user info

src/static/js/collab_client.js

@@ -414,6 +414,12 @@ function getCollabClient(ace2editor, serverVars, initialUserInfo, options, _pad)
     {
       callbacks.onServerMessage(msg.payload);
     }
+
+    //HACKISH: User messages do not have "payload" but "userInfo", so that all "handleClientMessage_USER_" hooks would work, populate payload
+    //FIXME: USER_* messages to have "payload" property instead of "userInfo", seems like a quite a big work
+    if(msg.type.indexOf("USER_") > -1) {
+      msg.payload = msg.userInfo;
+    }
     hooks.callAll('handleClientMessage_' + msg.type, {payload: msg.payload});
   }