Patch for /trunk/src/lang-vb.js

```
Added Using to the list of Keywords.
```

Original issue reported on code.google.com by `Lyle.Har...@gmail.com` on 14 Jan 2015 at 8:25

Attachments:
- [lang-vb.js.patch](https://storage.googleapis.com/google-code-attachments/google-code-prettify/issue-362/comment-0/lang-vb.js.patch)
