Actually reload user managers and backport unit reload macros
    
    The macro expansions would only work when compiled with a recent version of
    systemd. We don't want to create a dependency loop like this, let's just expand
    the string manually.
    
    Also backport the patch adding %systemd_postun_with_reload and
    %systemd_user_postun_with_reload so a FPC documentation change can be filed.