Ignore some *Box classes for attribute detection
Ignore some *Box classes for attribute detection

andrewleech/WeasyPrint,jasco/WeasyPrint,prepare/TestWeasyPrint,prepare/TestWeasyPrint,Kozea/WeasyPrint,Kozea/WeasyPrint,andrewleech/WeasyPrint,marclaporte/WeasyPrint,marclaporte/WeasyPrint,jasco/WeasyPrint