[ci skip]

this argument is passed by reference, but would be more efficient if passed by value

Add maintenance badge [ci skip]

And reintroduce `set_completer`.

[ci skip]

We must redraw the line with the original prompt
when the command used to validate/exit the loop is a movement.

Reuse undo::Changeset to retrieve last inserted text.
Introduce Cmd::Replace(Movement, Option<String>).
Refactor Cmd::Kill handling.

Do not catch interrupted error when SIGWINCH signal is received

Not tested