trait edit

Related to <a href="https://ebi-forecast.igb.illinois.edu/redmine/issues/2351">#2351</a>, <a href="https://ebi-forecast.igb.illinois.edu/redmine/issues/2198">#2198</a> and <a href="https://ebi-forecast.igb.illinois.edu/redmine/issues/2245">#2245</a>(only the second part; the first part has already been merged in a previous pull request)
This is "brand new" code, and I haven't had a chance to look it over yet.