Redefine module's connection with its localization file.
- Previously, modules read localization file from its own directory
structure (e.g., Scripts/Modules/Hello/Locales/). This update
makes all modules to use one unique localization files, the
Scripts/Locales/${LANG}/tcar.po file.
- Previously, the TEXTDOMAINDIR variable was not printed in debugging
output. Now it is.