Please cherry-pick:

Please cherry-pick:
- removed setter/getter and any other action methods from interface as this is
  no longer accepted
- rewrote broken getter calls to event-based notification of other beans
- removed obsolete language backing-bean property from localizationController
  because the already stored Locale instance does already have a 2-letter
  language code
- introduced changeLocale() for encapsulation of setting locale in bean, view
  root and triggering event for bean notification
- added ValueChangeEvent listener method for locale selection box

Signed-off-by: Roland Häder <roland@mxchange.org>