rlgwebd.js: refactor some game-starting code. Separate things like checking for games in progress, starting a new game, and figuring out where the lockfile and ttyrec should go. This allows e.g. the games-in-progress check to be used to create status messages. It also keeps the argument list for the TermSession constructor to a sensible size.

html {
	background-color: #C0FFC0;
	color: #101040;
}

h1 {
	text-align: center;
}
div.modal {
	clear: both;
}