考虑为core::path增加一个获取临时目录的功能

```
What steps will reproduce the problem?
1. 考虑为core::path增加一个获取临时目录的功能
2.
3.

What is the expected output? What do you see instead?


Please use labels and text to provide additional information.


```

Original issue reported on code.google.com by `602...@gmail.com` on 12 Jan 2012 at 5:27
