2004/03/09 Duane Wessels

    Added filter support.  Filters can be used to restrict the input
    stream to queries with certain characteristics.  The currently
    defined filters are:

    unknown-tlds        Only includes queries for TLDs that are
			bogus.  Useful for identifying hosts/servers
			that leak queries for things like "localhost"
			or "workgroup."

    A-for-A             Only includes A queries for names that are
			already IP addresses.  Certain Microsoft
			Windows DNS servers have a known bug that
			forward these queries.

    rfc1918-ptr         PTR queries for addresses in RFC1918 space.
			These should never leak from inside an
			organization.

2003/11/13 Mark Foster <mark@foster.cc>

    Added 'c' to display options. This screen will combine the
    source and sld fields to show "who is querying for what" -
    reason: we see alot of duplicate querys for whatever reason.
    This will help separate the legitimate queries from the broken
    resolvers, etc. See http://www.circleid.com/article/102_0_1_0_C/
    for more about that.
