Used for merge

*Delete the script codes.
*Modify the copy right
*Add --enable-winrtapi to configure
*Modify the doc/platform.texi
*change restrict to av_restrict, this should be a bug in compiling.
English grammar:

```
@item If you wish to compile for Windows RT, for either Windows Store or 
Windows Phone, add @code{--enable-winrtapi} to your configure options. You must
use static library for Windows RT.
```