1. fili <- names(urls.)
2. dati <- fili
without its extension, i.e., the part
following the last '.'
3. for(i in 1:length(url.)try(download.file(url.[i], fili[i]));
found[i] = TRUE
if something found and FALSE if not.
4. Return a character matrix with 4 columns: data = dati, file =
fili, url = url., and found.