Æ,æ,Ø,ø,Å,å danish letters in barcode data

[mladjenigor]

Hello,
I'm creating DATA MATRIX barcode, but, when data contain any special chars like danish letters (Æ,æ,Ø,ø,Å,å), created barcode cannot be scanned.

Creating barcode and saving in png file:
$barcode = new Barcode();
$barcodeObj = $barcode->getBarcodeObj('DATAMATRIX', 'Some string with Æ,æ,Ø,ø,Å,å chars', 150, 150);
$barcodeName = $this->upload->getRandomFileName() . '.png';
$path = $this->upload->getPath($barcodeName, false);
$barcode = $barcodeObj->getGd();
imagepng($barcode, $path);

Importing png image in pdf using mPdf lib
$mpdf->Image($path, x, y, w, h);

[tasmaniski]

this PR will fix the issue
#40

[nicolaasuni]

Unfortunately the PR is breaking existing tests.
Maybe the tests have to be fixed but the PR is incomplete.