Implement str_vprintfa() by making vsnprintf() write directly to the string. This also avoids excessive memory usage with strings allocated from data stack.
Implement str_vprintfa() by making vsnprintf() write directly to the string.
This also avoids excessive memory usage with strings allocated from data
stack.

--HG--
branch : HEAD

dscho/dovecot,dscho/dovecot,dscho/dovecot,dscho/dovecot,dscho/dovecot