correct several bugs: mkdir include, permissions, using original image's md5 to calculate 'set' path, etc. caching is now working
correct several bugs: mkdir include, permissions, using original image's md5 to calculate 'set' path, etc. caching is now working

rflynn/imgmin,micmro/imgmin,pornel/imgmin,rflynn/imgmin,micmro/imgmin,rflynn/imgmin,micmro/imgmin,pornel/imgmin,micmro/imgmin,jibsen/imgmin,jibsen/imgmin,jibsen/imgmin,rflynn/imgmin,pornel/imgmin,pornel/imgmin,jibsen/imgmin