Redesign initialization script.
    
    - Previously, automation scripts were initiated by executing the
      centos-art.sh script. The name of this script diverges from tcar,
      The CentOS Artwork Repository abbreviation, that is being used to
      name variables inside the script and function files related to it.
      This update renames the initialization script from centos-art.sh to
      tcar.sh in order to retain the name relation as much as possible.
    
    - Previously, definition of global variables, related to script
      initialization, were stored in the centos-art.conf.sh file.
      Configuration options are no longer managed inside automation
      scripts.  Instad, they are moved to configuration files that are
      read by automation scripts at demand. In order for users to
      customize these configuration options, the configuration file is
      stored in ${HOME}/.tcar.conf file when the workplace is prepared by
      automation scripts. This update moves global variable definitions
      from centos-art.conf.sh file to tcar.sh file and removes
      centos-art.conf.sh file.
    
    - Previously, automation scripts were conceived to work as integral
      part of the repository itself. It was difficult to produce final
      content for a directory structures outside The CentOS Artwork
      Repository itself. This update changes path information inside the
      initialization script to consider the tcar.sh script a standalone
      application that you install in your workstation (e.g., using an rpm
      package) and can execute over arbitrary number of places in your
      workstation in order to produce final content inside them.
    
    - The script version was set to 0.8 internally.