Updated scoring provides more succinct results

* Add a whitelist for domains not to lookup. This removes noisy domains an analyst already understands.
* Use SHA2 vs. MD5 for VirusTotal lookups. This gets rid of a surprising number of false positives.
* Use the ```found``` flag for OpenDNS domain lookups. This is better than ```status == 0``` for knowing if OpenDNS actually knows about a domain.
* VirusTotal domain lookups are hard to score. They generate more false positives than is useful. Changed the AnalyzeFilter to do fewer VT domain lookups.
How about filtering out domains using the whitelist before looking up the domains using VirusTotalApi? It'll save a few callouts and a (very) little bit of time.