Fix horizontal negative margins for floats
Fix horizontal negative margins for floats

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