don't create a new chatmodel from client..that's a leak, i'm sure

forgot to transition away from the client creating it. Game:: would always
call client::setchatmodel because it needed to retrieve it from the qml
instantiation. but client would (before this) make a new one too.

chat works just the same still.
no need for hardcoded import path

seems we don't need it anyways? it only would've worked on my system only
anyways, haha. must've been left from me testing something.
fix calling game-connection-required in game loop, when not connected

(i never tested the case of no --play-now, on the port to qt)

now it doesn't crash, doesn't show backbuffer garbage
bind chatview.visible to gameconnected

works automagically :)

also fix emit gameConnected() usage. that was just the getter, use
gameConnectedChanged(). typo, of some form.
seriously cleanup stackview popping
make backgruond rectangle (black) so we don't see glclear color anymore

on main menu, that is
oops, wrong name