Review P3-1: a "No such file or directory" line from another program
(cat, ls) no longer counts. Only bash's "line N:", dash's "N:" and env's
quoted form do.
P3-2: a name with a run of 16 letters and digits looks like a key, so it
stays in the run's private stderr instead of the reply.
P3-3: a 16 KiB stderr window that starts mid-file drops its partial first
line, so a cut name ("aude") isn't reported.
P3-4: CRLF lines read the same as LF lines.
P3-5: tests for the name check (tokens without spaces, key-shaped names),
for a cat line, and for the window boundary through the runner.
jason.woltje
387f73a7a4