* When building with MSVC, there is no snprintf function, but there are
_snprintf, vsnprintf, and _vsnprintf functions (as well as many
variations on these). The MSVC _snprintf is not the same as C99's
snprintf, and in particular, it does not guarantee that the buffer is
NUL-terminated, whereas C99 does guarantee this. I want the C99
behavior, so add a c99_[v]snprintf functions in shared/c99_snprintf.h
that provide C99 behavior.
* Details:
http://stackoverflow.com/questions/2915672/snprintf-and-visual-studio-2010
