new bc files

I put a zipped tar-ball called "bcfiles.gz" of the used bc-files on the server.
The only change is in file extensions.bc (the basic one) in function factorize(n): the return value is now 0 for n=0 or n=1, 1 for prime numbers and the number of primefactors for any other number. Before it was -1, 0 and no.of primefactors.
If you dont use this functio a lot you might not want to download it...