Fix test-execute by wrapping *err* Writer in a PrintWriter
…ly call printStackTrace
Move data/ to resources/.
Unfortunately with the way I'm using branches sequentially, it means a change to any branch cascades down in merges to all branches after it. Sorry for the noise, but it seems to be the only way to keep things consistent.
Explain that using a def in a function body is not OK unless it's a function that runs only once.