Merge pull request #144 from johnheroy/master

Overview of SimpleGame and Room classes in README
remove players who disconnect
delete disconnected users from firebase
also delete from Room.player object on disconnect
end game if host disconnects
remove redundant .remove() calls in room.js
Player, DisplayName, OtherPlayer docs
gamescore docs
Merge pull request #145 from concreted/remove-players

remove guests on disconnect, end game+delete room if host disconnects