Translations are looked for in ./translations

Previously, there was a convention of putting .pot and .po files for translations under each module's and theme's ./po subdirectory. Although this was just a common convention, and only Autolocale module was dependent on it, Drupal 6 includes most of Autolocale's functionality and for user friendliness renamed the directory to ./translations. Modules and themes should have their translation templates and translations under the ./translations directory, so that Drupal 6 imports them automatically.

Converting 5.x modules to 6.x