systemd: Escape machine name for machined
    
    According to the documentation, CreateMachine accepts only 7bit ASCII
    characters in the machinename parameter, so let's make sure we can start
    machines with unicode names with systemd.  We already have a function
    for that, we just forgot to use it.
    
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1062943
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1282846
    
    Signed-off-by: Martin Kletzander <mkletzan@redhat.com>