RosettaCode factorial needs to use longs

[bearophile]

Jay Norwood:

> http://rosettacode.org/wiki/Factorial#D
>
> to whomever is maintaining these:
> Need to change all ints to longs in this example to get the 
> displayed results since the 15! result requires more than 32 
> bits.

I am maintaining the D entries, I have fixed that factorial code, 
thank you. I don't know why the shown output was for 64 bit 
numbers.

Bye,
bearophile