spamassassin: 13 new tests. Moved config loading

into register() with callback

remaining changes are to improve testability
Merge pull request #667 from msimerson/spamassassin

spamassassin: 13 new tests. Moved config loading
removed 2 duplicate methods, remove $int-level-domains
fixed reference
data.uribl: replace top_level_tlds with is_public_suffix
net_utils: s/jslint/jshint/
uribl: don't log useless ENOTFOUND message

Not being listed on a DNSBL is not an error
mf.resolv: don't report no DNS results as warning
net_utils: cleanups to reduce size of diff
net_utils: updated public suffix list