much much restructurating and commenting. Start new chat feature now
works when a user was already engaged in another chat, and other user is
notified that peer has left the chat
series of bug fixes, especially concerning - peer left - events
made leaveCurrentChat(), which disconnects a user from his/her current peers. Used when changing chat rooms and on socket disconnect events
implemented (and thoroughly tested) group chat feature. Scrapped unused functions.
implemented group size limit (but users are not yet notified when this occurs