Update tuneup module inside centos-art.sh script.
    
    - Previously, tuneup module did not work as expected in the current
      modular design because function and variable names inside it had the
      wrong names. This commit uses correct function and variable names
      inside tuneup module.
    
    - Previously, when processing html page,  there was not feature for
      transforming (probably malformed) HTML files to XHTML. This commit
      adds a cleanup feature to transform HTML into a valid XHTML page
      using sed and xmllint.
    
    - Previously, when processing sh files, there was not a feature to
      transform variable names from $varname to ${VARNAME}. The ${VARNAME}
      naming convention is being adopted inside centos-art.sh script as
      default naming convention for variables. This commits adds the
      sh_setVariableNames function to transform variable names from
      $varname form to ${VARNAME} form.
    
    - Previously, tuneup module tried to synchronize changes from local
      working copy to central repository using cli_synchronizeRepoChanges
      functions. This commit removes repository synchronization from
      tuneup module.
    
    - Previously, when reading command-line, tuneup module supported the
      help,quiet,filter:,answer-yes,synchronize as command-line options.
      From these options only help, version and filter were useful. This
      commit removes quiet, answer-yes and synchronize options from tuneup
      module's command-line and adds version to it.
    
    - Previously, when reading the module's help, tuneup module used the
      cli_runFnEnvironment function to read documentation in texinfo
      format. Texinfo format is no longer supported for documentation
      inside centos-art.sh script. It was replaced by asciidoc which is
      used to produce documentation in different formats, including
      manpages. This commit updates the way tuneup module reads its
      documentation by using tcar_printHelp function instead.
    
    - Previously, in tuneup_getOptions function, we were using the
      cli_parseArgumentsReDef function to redefine the ARGUMENTS
      environment variable. This commits renames the ARGUMENTS variable to
      TCAR_ARGUMENTS and performs its value redefinitions by modifying the
      TCAR_ARGUMETS variable directly, just after stripping out the
      options values from it.
    
    - Previously, the topcomment.sed file, used to update the top comment
      section of Bash scripts did not add the "Written by:" line. This
      commit adds the "Written by:" line and my full name along with
      contact information in the next line.
    
    - Previously, when reading tuneup modules' documentation there wasn't
      any to read about. This commit adds the tuneup.asciidoc with an
      initial documentation structure to fill up and the render.conf file,
      both inside tuneup module's Manuals directory. Manpages and
      xhtmlpages will be generated after running the render functionality
      over the tuneup module's Manuals directory.
    
    - Previously, when building the list of files to process, tuneup
      module looked up for svg, xhtml and sh file extensions only. With
      this commit, tuneup module looks for .svgz, .svg, .shtml, .xhtml,
      .html, and .sh file extensions.
    
    - Previously, inside the sh files, the top comment used the minus (-)
      character to draw top comment boundaries. This commit changes sh
      files to use the number sign (#) as top comment boundaries, instead.