Comment 15 for bug 1616861

Test program can be compiled e.g. like this:
gcc $CFLAGS -D__TEST__=1 -DMDNS_DEBUG=1 -DMDNS_STDERR=1 mdns.c

The test program is useful for checking mdns responses to
various queries in the network. Run without arguments to scan
for scanners, and with host name argument to run a simple
name lookup.