start chatting a bit

- fixed: popup to add friend is shown as many times as + was clicked
- send message as pending, wait for recipient to receive it first
- receive and show messages
- update status

- added isRegistered to EventCentral
main: load luce first thing to be compatible with luce-embeddable
DTBar: use LApp's getRes
DTUser: use LApp's getRes
DTChat: use LApp's getRes
DTChat: send message when return is pressed, but add a new line instead when a modifier is pressed