- web_set_locale returns the language and the country for lang/country
  combinations (eg. de-AT) in the language field.  Correct?
- add conversion modules for other Unicode encodings than UTF-8 
  (UTF-16, UCS-*)
- Better support for Windows, the locale detection stuff does not
  really work there.  Any help would be appreciated.
- Check whether other locale categories than LC_MESSAGES work.
- Avoid call to __load_domain in Locale::gettext_pp, use a cache table
  first
- The pure Perl version of gettext will always look for message catalogs
  in /usr/share/locale/{LANGUAGE}/LC_MESSAGES after the directory
  specified by bindtextdomain().  This can lead to undesired results.
  But I think the C version from libintl does the same, correct?
- Allow to dynamically expand the list of supported conversions
- Allow to dynamically restrict the list of suppported conversions