[tor-relays] fast exits running 'unbound' should switch to 'named'

[Michael McConville]

Dhalgren Tor wrote:
> Bug #18580: exit relay fails with 'unbound' DNS resolver when lots of
> requests time-out
> 
> https://trac.torproject.org/projects/tor/ticket/18580

I wouldn't go that far. I've been running with Unbound for ~1.5 years
now (AFAIK) without issue. I've also been told that the code is of
significantly higher quality and that it's considerably more secure.