Search harvested repos for instances of stack traces that appear in issues on the repo or stack traces

[sangheestyle]

From Ken,

Search harvested repos for instances of stack traces that appear in issues on the repo or stack traces in commit logs (even small snippets of stack traces)

This will involve coming up with a set of heuristics for how to search for stack traces: i.e. search for the words "Exception" and "throws" in the indexed documents and then see what comes back to identify other terms that can be used to find stack traces.