i18n of categories package. Mostly all of the interface are now internationalized, probably a couple are missing. Bumping up version so catalog files are loaded. New message keys added on en_US and de_DE catalogs.
- slightly extended message catalog - fixed localization in context bar - added new context variable ctx_id used for permission checking. This optional variable allows to specify category clients to provide am object, on which permissions are checked for adding categories. This has the advantage that package_admin could be allowed this way to add categories without needing explicit rights on the categories package.