qemu pcap networking should now work

[Juergen Lock]

Hi!

 jkim@ sent me an update to the pcap patches a few days ago that fixed
the packet delays (thanx!) and after we also found out the oversize
packets were caused by TSO on the em(4) interface here I now updated the
qemu and qemu-devel ports.  This is the note I added to the pkg-message.s:

- The pcap code (-net nic... -net pcap,ifname=...) should work properly
now, with only one exception:  Advanced features like TSO used on the host
interface can cause oversize packets which now do get truncated to avoid
confusing/panicing guests but of course still will cause retransmissions.
So if you see slow throughput and `pcap_send: packet size > ..., truncating'
messages on qemu's tty try disabling TSO etc on the host interface at least
while using pcap.

 Enjoy, :)
	Juergen