cocos creator 2.3.3版本
以__开头的value，如果键值对很多，解析后key的value是空
例如类似这样的：
{"100101":{"__id__":"100101","id":100101,"name":"skill_100100_name","memo":"skill_100100_memo","skill_key":100,"level":1,"skill_type":1，... ... }, ... ...}
cocos creator 2.3.3版本
以__开头的value，如果键值对很多，解析后key的value是空
例如类似这样的：
{"100101":{"__id__":"100101","id":100101,"name":"skill_100100_name","memo":"skill_100100_memo","skill_key":100,"level":1,"skill_type":1，... ... }, ... ...}