Update prepare module from centos-art.sh script.
    
    - Remove images, links and manuals options and add repository option
      instead of them. They are no longer needed inside prepare module.
      Production tasks related to images, links and manuals are taken by
      render module now.
    
    - Rename function from prepare_setConfiguration to
      prepare_setRepository.
    
    - Update centos-art.asciidoc.