The Lua Class is not a meta table now. It is a normal table, has a key n...

提供了tolua.getbackup接口获取在Lua被覆盖的c函数。注意如果没有被覆盖的话，将会返回nil。具体可见Commit时的注释。
使用示例：

function CCNode:setPosition(x, y)
	print("----CCNode:setPosition("..x..","..y..")")
	local func = tolua.getbackup(CCNode, "setPosition")
	if func then return func(self, x, y) end
end