Plus my changes:
- walking process group fix in foregrounding a job.
- reset of process group in parent shell if interrupted before the wait.
- move INTON lower in the dowait so that the job structure is
consistent.
- error check all setpgid(), tcsetpgrp() calls.
- eliminate unneeded strpgid() call.
- check that we don't belong in the process group before we try to
set it.
symlinks. From Chris Demetriou <cgd@NetBSD.ORG>. Fixes PR #1776.
Changed so that INTOFF/INTON are paired in getpwd(). From Matthias
Pfaller <leo@marco.de>. Fixes PR #2130.