daemon-util: provide rotate_logs and rotate_all_logs actions

Modify daemon-util to allow sending SIGHUP to one or all daemons. This is meant
as a utility function to be used in logrotate definitions.

Signed-off-by: Apollon Oikonomopoulos <apoikos@gmail.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>