Update centos-art.conf.sh file.
    
    - Remove GPG fingerprint from top comment.
    
    - Add first year to copyright line.
    
    - Remove TCAR_FLAG_SYNCHRONIZE variable. It is no longer used.
    
    - Reset the script version set at TCAR_SCRIPT_VERSION from 0.5 to 0.4.
      In order to match the repository version release. Luckily, the
      script hadn't been released to public using any of these numbers,
      yet. The last version number used for public release was 0.3.
    
    - Update comments' design.