no fixed port numbers in use anymore. Starting now, the default ports the
servers use are 8990 - 8993. There's no option to modify these yet, but
changing the $base option in the top of the runtests.pl script.
multiple DNS lookups can run simultaneously faster. The downside is that
resolving the same host name now can be made at once from multiple threads,
but the upside is that threads now don't alwys have to wait for the others'
resolves. Test case 506 updated accordingly.
