Reorganize files related to prepare module.
    
    - Previsouly, the word "workplace" was used on function names to
      identify their purpose. This word differ from variable names which
      uses the "workdir" name. This update changes function names related
      to prepare module from "workplace" to "workdir" in order to be
      consequent in naming both function and variable names.
    
    - Add prepare_printUsage function. This function is called when no
      path is provided as argument in the command-line.
    
    - Previously, no verification was performed about the path information
      entered in the command-line. This update uses the tcar_printPath
      function to transform the path provided in the command-line into a
      valid path before using it.
    
    - Previously, both .conf.tpl and .conf file were considered as
      possible configuration files to be used as reference to build the
      working directory. This brings confusion about what files must be
      produced as part of the repository (e.g., documentation,
      localization) and what files shouldn't (e.g., design models). This
      update changes prepare_getWorkdir and prepare_getWorkdirConf
      function to retrieve .conf.tpl files only and exclude .conf files.