Fix FTBFS and various other issues
    
    - BR: systemd-units for %{_unitdir} macro definition (fixes FTBFS #992118)
    - Put tmpfiles config in %{_tmpfilesdir}, not under /etc
    - Package installation creates %{_localstatedir}/run/%{name} (#909272, #957355)
    - Service files are not executable
    - Require perl(Digest::SHA1) (#909258)
    - Wait for name resolution to be available before starting (#905553)