Remove unneeded eth_dst from raw packets.

This was causing errors when trying to send to someone not in the
current broadcast domain, of course. Rather silly for me to have put it
in there in the first place.
Update gemspec/changelog
Release v08.6, bugfix for send_raw_*

Fixes issue where I was stupidly trying to arp the destination,
limiting it to work only on the local broadcast domain.