Update to 1.847
    
    - New upstream release 1.847
      - Obsolete RedHat MCE-1.840-Sereal-deps.patch file; this patch file is no
        longer needed and finally resolved with this release
      - PDL random numbers now unique between threads:
        see https://www.perlmonks.org/?node_id=1214439
      - Replaced "PF_UNIX" with "AF_UNIX" in MCE::Util