barcode/widgets.py: workaround problems with new style class inheritance
barcode/widgets.py: workaround problems with new style class inheritance

kanarelo/reportlab,Distrotech/reportlab,Distrotech/reportlab,kanarelo/reportlab,kanarelo/reportlab,kanarelo/reportlab,Distrotech/reportlab,kanarelo/reportlab,Distrotech/reportlab,Distrotech/reportlab