throw exceptions on errors in AVTDriver instead of returning None
throw exceptions on errors in AVTDriver instead of returning None

jlegendary/SimpleCV,jlegendary/SimpleCV,gskielian/SimpleCV,jlegendary/SimpleCV,hayd/SimpleCV,tpltnt/SimpleCV,sightmachine/SimpleCV,hayd/SimpleCV,hurdlea/SimpleCV,nils-werner/SimpleCV,sightmachine/SimpleCV,sightmachine/SimpleCV2,sightmachine/SimpleCV,jlegendary/SimpleCV,onaclovtech/SimpleCV,onaclovtech/SimpleCV,sightmachine/SimpleCV2,jyt109/SimpleCV,jlegendary/SimpleCV,jyt109/SimpleCV,hayd/SimpleCV,jyt109/SimpleCV,hayd/SimpleCV,gskielian/SimpleCV,hurdlea/SimpleCV,sightmachine/SimpleCV,tpltnt/SimpleCV,hayd/SimpleCV,hurdlea/SimpleCV,gskielian/SimpleCV,onaclovtech/SimpleCV,sightmachine/SimpleCV2,nils-werner/SimpleCV,hurdlea/SimpleCV,jyt109/SimpleCV,beni55/SimpleCV,nils-werner/SimpleCV,nils-werner/SimpleCV,jyt109/SimpleCV,gskielian/SimpleCV,gskielian/SimpleCV,nils-werner/SimpleCV,hurdlea/SimpleCV,sightmachine/SimpleCV2,tpltnt/SimpleCV,beni55/SimpleCV,sightmachine/SimpleCV,tpltnt/SimpleCV,onaclovtech/SimpleCV,tpltnt/SimpleCV,onaclovtech/SimpleCV,beni55/SimpleCV,beni55/SimpleCV,beni55/SimpleCV