[ feature request ] Exit if all processes stop

[yonas]

It would be nice if, by additional CLI flag, mprocs could automatically quit when all process have stopped, so long as all processes exit with status code zero.

An additional flag would enable mprocs to automatically quit even if one or more processes exited with non-zero.

[yonas]

The two flags can be combined into one. For eg.

--exit-after-stop
--exit-after-stop-when=success      Exit when all processes have successfully stopped with exit code zero. This is the default.
--exit-after-stop-when=failure      Exit when all processes have stopped, regardless of exit status.