dns-audit.bro: added new script
dns-audit.bro: added new script

This script is intended to catch hosts making DNS queries
to DNS servers other than those defined as local DNS servers.

This works well on small networks where all queries are intended
to go through a handful of internal DNS servers.

jonschipp/bro-scripts,unusedPhD/jonschipp_bro-scripts,jonschipp/bro-scripts,unusedPhD/jonschipp_bro-scripts