fix a problem about class file path.

 I met a problem on Winodws,so I changed the code.It fixed. :)

```php
$path = 'path\to\file';				// path on Windows
var_dump( stripslashes($path) ); 	// output: 'string(10) "pathtofile"'
var_dump( addslashes($path) );		// output: 'string(10) "path\\to\\file"'

$path = 'path\\to\\file';			// path on Windows
var_dump( stripslashes($path) ); 	// output: 'string(10) "pathtofile"'
var_dump( addslashes($path) );		// output: 'string(10) "path\\to\\file"'

$path = 'path/to/file';				// path on Linux
var_dump( stripslashes($path) );	// output: 'string(12) "path/to/file"'
var_dump( addslashes($path) );		// output: 'string(12) "path/to/file"'
```