fixed : deprecation warning with the module "sets" when using python 2.6
fixed : deprecation warning with the module "sets" when using python 2.6

mhaberler/Canfestival-3,mhaberler/Canfestival-3,mhaberler/Canfestival-3,mhaberler/Canfestival-3,mhaberler/Canfestival-3,mhaberler/Canfestival-3