Don't initialize the audio buffer passed to the application's audio callback, since they are expected to entirely fill it with data or silence. For legacy apps that might expect the buffer to already have silence and thus may not fill the buffer in the callback, there's an environment variable to expose the old behaviour. Fixes Bugzilla #416.

#!/bin/sh
#
# Regenerate configuration files
cp acinclude.m4 aclocal.m4
found=false
for autoconf in autoconf autoconf259 autoconf-2.59
do if which $autoconf >/dev/null 2>&1; then $autoconf && found=true; break; fi
done
if test x$found = xfalse; then
    echo "Couldn't find autoconf, aborting"
    exit 1
fi