bmxtranswrap: add --afd option to set/override afd prop
bmxtranswrap: add --afd option to set/override afd prop

stuarthicks/bmx,xunchangguo/BMX,kierank/bmxlib-bmx,ebu/ebu-bmx,stuarthicks/bmx,xunchangguo/BMX,Limecraft/ebu-bmx,kierank/bmxlib-bmx,kierank/bmxlib-bmx,stuarthicks/bmx,Limecraft/ebu-bmx,Limecraft/ebu-bmx,ebu/ebu-bmx,xunchangguo/BMX,ebu/ebu-bmx