Update prepare module from centos-art.sh script.
    
     - Remove prepare_seeEnvironment, prepare_updateEnvironment and
       prepare_getEnvars functions. I don't see any use for them. So,
       clean up.
    
     - Remove prepare_updateLocales function. There isn't need to produce
       locale files at first stage. They all will be under version
       control and managed by locale module.
    
     - Remove unused options from prepare_getOptions.
    
     - Rename prepare_update* functions to prepare_set* functions.
    
     - Change link rendition process. Previous to this commit, links were
       produced in the prepare_updateLinks function. In this commit, the
       function prepare_updateLinks is just an interface to
       prepare_setConfiguration which builds a list of all links.conf
       files inside the repository and sends it to render module.
    
       I found that configuration files are more flexible and adaptable to
       changes inside the repository directory structure than having all
       links definitions inside an script using variables. Note that
       configuration files are always inside directories and work relative
       to them, if you move the directory to another place the links will
       be created using the new location, the next time you run the render
       module over them.
    
     - Change images and manuals rendition process. Now they all are based
       on configuration files and handled by render module.
    
     - Add prepare.asciidoc file. This file holds the module's
       documentation. If you want to know the module's options and how to
       run it, see this file. It is also used as source to produce
       documentation in other formats like manpage.
    
     - Add prepare.conf file. This file contains all configuration
       variables related to prepare module.