world offset considered
Merge branch 'yifei' of https://github.com/yutongp/RaiseMeUp into ypei

Conflicts:
	server/rpc/demo.js
merged with ypei
Merge branch 'xinbweng' of https://github.com/yutongp/RaiseMeUp into ypei
return bug of can go directions fixed
Merge branch 'yifei' of https://github.com/yutongp/RaiseMeUp into ypei
Merge branch 'xinbweng' of https://github.com/yutongp/RaiseMeUp into ypei
ball can move !!!!
add more features
add water
fix bug with move
Merge branch 'yiweili' of https://github.com/yutongp/RaiseMeUp into ypei

Conflicts:
	client/code/app/game_client.js
Merge branch 'xinbweng' of https://github.com/yutongp/RaiseMeUp into ypei

Conflicts:
	client/code/app/game_client.js
Added gameOver window