Update render_doDm.sh:
    
        - Now, instead of creating the temporal directory in the output
          directory and process it there, we create the temporal directory
          through `cli_getTemporalFile' and create the tar.gz file there.
    
        - The way files are copied changed too. The files common to GDM
          and KDM (e.g., centos-symbol, centos-release, THEME_NAME.xml,
          GdmGreeterTheme.desktop, etc.) are copied just once to the
          temporal directory.  Then, we loop through all screen
          resolutions provided and try to build one display manager theme
          for each one of them; using the common information already
          available in the temporal directory.
    
        - When the tar.gz file is created, it is moved up to the output
          directory.
          
        - When all tar.gz files are created and moved up to the output
          directory, the parent temporal directory ---that we created
          through `cli_getTemporalFile'--- is removed.
    
        - Previous to this update, errors may rise if you try to produce
          the same GDM or KDM at the same time, running the same command
          twice or more in different terminals. This problem has been
          corrected in this update, but you probably don't need to run the
          same command twice (or more) to produce the same content at the
          same time.