See: https://go.dev/doc/go1.19#go-doc
Do not trigger an error upon parsing argument starting with underscores. _netdev was already ignored after parsing.
This is possible now that we no longer support go1.12 and brings rclone into line with standard practices in the Go world. This also removes errors.New and errors.Errorf from lib/errors and prefers the stdlib errors package over lib/errors.
