better error logging added.
close #16 by creating a queue for modeling changes to avoid trying to concurrently access R. Additionally, the notifier is a part of this as it can also fail if sending e-mail at the exact same time.
Performance enhancement. Instead of blacklisting certain extentions that are likely not source files, we are now whitelisting all common code and script file extentions. The linking algorithm really suffers to unreasonable performance when doing massive changes that usually are seen in changelogs or documentation, and therefore now we completely exclude them in the SZZ corrective to bug inducing commit linking.