test: add a mini-workflow using `nohup_sedsid`
lib: show target-status-info in `$EDITOR`

It is optional, with the key 'v' one chooses between `Inline` and
`$EDITOR`.
lib: rename `nohup_setsid` to `daemonize`
lib: add notion of “hack-used” in `Deamonize`
lib: add the `Python_daemon` daemonization hack

The idea is to do what `nohup setsid` does by generating a python script
and running it.
This makes long-runnings on MacOSX possible.
test: add an example using the Python-daemon “hack”
lib: fix killing of python-daemons
lib: fix just-created then killed targets

This changes the “activated state” of those targets. It is a very minor
fix.
lib: add function `Target.Is.activated_by_user`
lib: use `activated_by_user` as a target-filter
lib: fix bug in Daemonize.update (1 character fix)

This uses `ps -g` instead of `ps -p` since the goal is to inspect the
process group not the first process of the group (which may die before
its children).
lib: improve visual feedback of interactive commands