Update render module of centos-art.sh script.
    
    - Previously, the language expansion when man pages were produce took
      place inside the render_setLocalizedXml function. The
      render_setLocalizedXml function is also used to localize other kind
      of document which doesn't require to make any language expansion
      fixing. So the language verification related to man pages was
      checked in places where it never applied. This update moves the
      language expansion related to man pages from render_setLocalizedXml
      to manpage module where it always is applied.
    
    - Previously, at asciidoc_setBaseRendition, there was one while loop
      to build the localized instances and one for loop to process
      localized instances created in the while loop. This update moves
      instance processing from for loop to while loop and removes the for
      loop from the function.  There is just one loop for both building
      and processing localized instances. As consequence, the DOCBOOK_FILE
      variable definition was removed from asciidoc_setBaseRendition
      function and the TCAR_INSTANCES array variable is used instead when
      you need to retrieve docbook localized instance inside child module
      environments.
    
    - Previously, neither svg nor asciidoc modules from render module did
      support any release translation markers. This made expansion of
      =RELEASE= and =MAJOR_RELEASE= translation markers to fail. This
      update changes svg and asciidoc modules from render module to
      support expansion of =RELASE= and =MAJOR_RELEASE= translation
      markers.
    
    - Previously, asciidoc_setFormatsRendition didn't include a default
      format in the case construction. Without a default entry in the case
      construction would leave the script in a uncertain state when a
      format different from that supported is specified. This update
      changes asciidoc_setFormatsRendition to add a default format entry
      in the case construction.
    
    - Previously, when no export id was specified, the svg module inside
      the render module defined CENTOSARTWORK as default export-id value.
      This made rendition of PNG files to fail when the CENTOSARTWORK
      export-id is not set inside the SVG file.  This update changes the
      svg module inside the render module to allow an empty export-id
      value. When no export-id value is provided to svg module inside
      render module, the export-area-drawing is used instead for producing
      the PNG file. This make rendition of PNG files very difficult to
      fail.
    
    - Simplify render_setLocalizedXml function.
    
    - Add missing top comments inside shell scripts.
    
    - Add render_setInstances function.