Update cli_getFilesList.sh and cli_printActionPreamble.sh:
    
        - The verification of FILES was moved from cli_getFilesList.sh to
          cli_printActionPreamble, again. 
          
          I thought that if make cli_printMessage output to standard error
          (/dev/stderr) there would be no problem with assigning the
          output of cli_getFilesList to a variable. If some error exist it
          would not be stored inside the variable because assignment is
          done from standard output no standard error. 
          
          I tested this in the shell prompt and seems to work that way
          there, but not inside centos-art.sh. I am missing something
          surely. Anyway, put FILES verifications (that includes whatever
          kind of output) inside cli_printActionPreamble.