Update `prepare' functionality:
    
        - Add `--images' and `--manuals' options to prepare images and
          documentation manuals, respectively, inside the working copy.
    
        - Define default behaviour when no option is provided.
    
        - Remove specific FLAG_* variables to start using ACTIONNAM and
          ACTIONNAMS variables when processing options arguments. This way
          it is possible to execute options' related functionalities
          arbitrarily and also consider global variables redefinitions
          (e.g., FLAG_QUIET, etc.) to affect the way options' related
          functionalites are executed.
    
        - Stop using `prepare_doLinksSuffixes' functionality. All common
          links created inside the working copy do use the `centos' suffix
          always.
    
        - Remove `prepare_doLinksSuffixes.sh' file.
    
        - Don't show action preamble message when user-specific
          configuration files are removed from/created in the user's home
          directory.
    
        - Remove specific FLAG_* variables verification from
          option-specific functionalities.
    
        - Update file comments.
    
        - Don't print action messages on options' related functionalities.