message: add presenceCallback option
diff: @@ -302,7 +302,17 @@ export default class Roster {
  if (presence !== Presence.offline) {
  // offline presence needs special handling in XMPPConnection
  - Client.getAccount().getConnection().sendPresence(<any>Presence[presence]);
  + let account = Client.getAccount();
  +
  + if (account) {
  + account.getConnection().sendPresence(<any>Presence[presence]);
  + }
  + }
  +
  + let presenceCallback = Client.getOption('presenceCallback');
  +
  + if (typeof presenceCallback === 'function') {
  + presenceCallback(presence);
  }
  });
  }
  