add another test to dns_list_base

to determine if the issue is with XML or multi
add a couple more tests, further testing.

these tests pass locally, but fail for Travis. Why?
define the array outside the call
dnsbl: replace forEach with async.each
dns_list_base: improved comments
update multi() call to skip tests for null zone
Merge pull request #746 from msimerson/dns_list_base

Dns list base
make ASN compatible with node 0.11
added check for DNS results
update two remaining tests with 'fix'
asn: test obj before accessing it
empty ASN results are now null/undefined (was '')
asn: log some more debugging
asn: use JS syntax for join
asn: replace a for loop with async.each and

dns_results now returns an error as the first result param
Merge pull request #751 from msimerson/asn

Asn
replaced util.isArray with Array.isArray