light editing on manual
Trying to trace down weirdness with location bugs.

I've been able to trace down one of them to cfg-parser, for
it doesn't exhibit a bug when running test-simple-line-drawing.rkt.
I'm getting the wrong location from cfg-parser, and need to hunt.
Doing some evil hacking on cfg-parser to get right location on matches.  Need to figure out what the correct way to do the patch, and then send upstream.