handler.handle_request: don't bother to spawn self.factory, just call it
read_thread_hixie_76: don't use with_timeout(), hixie_76 doesn't support ping anyway.

KQUEUE: new compile-time constant
only resize to result from wait_for_read() if using kqueue

Fixed ticks per second detection for Linux.

set_seed(): range check the seed string

seed the SURF generator
filter ipv6 addrs out of root_hints if !ipv6