fix(iframe): fix handling of res:// error for <=IE9 to have the possibil...

...ity to handle it from within the client app

This patch helps an application to roughly detect that the server responded with an error and not a status of 200.

Also it fixes one bug: html was out of scope for 
```
var xhr = {response: html, status: 200, dummy: true};
```

as html was defined inside the structure above of that in the try block.