Simplewallet should now resolve urls to addresses

Simplewallet should now do a DNS query on an address if it fails to
convert the given string to a binary representation of an address
(base58->binary).  It will prompt the user, telling of what the "url"
passed was, what monero address it translated to, and whether or not
DNSSEC validation was a success, and ask for a confirmation that these
are all acceptable.