The aim is to run pies in foreground if possible. Limit execution time
using external wrapper.
* src/pies.c: (_cb_redir): Consistently return 1 on errors.
* tests/aux/sleepexit: New file.
* tests/aux/startcheck: New file.
* tests/aux/touchfile: Change arguments.
* tests/aux/respawn: Rewrite.
* tests/lines.c: New noinst program.
* tests/to.c: New noinst program.
* tests/.gitignore: Add new programs.
* tests/Makefile.am: Update.
* tests/env.at: Use to to avoid hanging forever.
Add missing popdef.
* tests/redirect.at: Use echo as component program.
* tests/respawn.at: Run pies in foreground. Use to to limit execution
* tests/shell.at: Likewise.
* tests/shutdown.at: Likewise.
* tests/startup.at: Likewise.
* tests/ret-exec.at: Use sleepexit as component program.
* tests/ret-notify.at: Likewise.