Don't you think we should better to use Liuggio bundle helpers?

I mean, I also have a project using it, and some stuff can be handled by the bundle.
For example, I think we should manipulate the `xls.service_xls2007` service whereas the `phpexcel` one. Thanks to that, code in the admingenerator can be reduced (and so the less we have code on our side, the less risks of error are).

I think so we can make things just a little simpler (I agree that's not make a big difference), with something like:
```php
$excelHandler = $this->get('xls.service_xls2007'); // We can probaby make it configurable?
$excelObject = $excelHandler->getExcelObj()
// Populate properties
...
$sheet = $excelObject->setActiveSheetIndex(0);
// Create headers
// Populate data

// Make response simpler
$response = $excelHandler->getResponse();
$response->headers->set('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet; charset=utf-8');
$response->headers->set('Content-Disposition', 'attachment;filename={{ builder.filename }}.xlsx');

return $response;
```


Don't know if this really makes sens...

What do you think @bobvandevijver ?