Fix issue 3

Fixes https://github.com/nsue/multiplayer-breakout/issues/3
Revert BRICK_ROWS and BRICK_COLS to production values
Merge pull request #4 from nsue/fix-issue3-continuing-after-gameover

Fix issue3 continuing after gameover
able to see the ball release movement from other clients
able to see other clients' ball collision with bricks and paddles
client is able to enter mid-game and see the correct position and velocity of other client's ball (only for 2 players)
remote balls are assigned to remotePlayers object, balls are synced between 2 players
removed remoteBall variable from the outermost scope
fixed bug where existing player balls are duplicated
client's remote ball is killed when disconnected, only works for 2 players
fixed bug where player was not removed from remotePlayers when disconnected
implemented don's fix for onremoveplayers, balls are now synced across multiplayers
remove event handler: kill disconnected ball
fixed bug where remotePlayerBall is called in onBrickKillToOtherClients when it is still undefined
uncommented closure on game.js
added createRemoteBall helper
remote balls and paddles merged