Refactored file headers for po-packager compatibility

This patch refactor's the "header" of all po files. It reorganizes the copyright and make the template looks like drupal-pot template style additional add the most important lines we need for po-packager like

# German translation of Drupal (modules/throttle/throttle.module)

to the third line and therefor allow us to package the translation files with PO-Packager (http://cvs.drupal.org/viewvc.py/drupal/contributions/tricks/po-packager/) for D6 testing and later production. This task is mandatory for future - it must be done. Now this doesn't change the translation strings them self, but it helps us to test translation features for D6.