added a vsnprintf() implementation from cvslock. See the notes on the

added a vsnprintf() implementation from cvslock. See the notes on the
license at the top of lib/snprintf.c

I've always been slightly uneasy about our half-baked vslprintf()
implementation and the risks on platforms that don't have vsnprintf()
so when I saw this code in another GPLd package I wanted it for Samba.