Please cherry-pick:

Please cherry-pick:
- data output by a p:dataTable with pagination, filtering and sorting cannot
  come from a request-scoped bean as each AJAX request will reset the
  filteredValue-referenced bean property to null which leads to an empty table.
- better is to have a separate backing bean on view-scoped which holds both
  lists, the full ("all") list and filtered list (which are the items that have
  passed the filter).
- also had to update converters and validators
- finally, no need for javax.faces.STATE_SAVING_METHOD=client anymore! yeah!
- rewrote menu system (admin at least, guest and user login is following) to a
  menu-bar-based system which saves a lot space and is a more modern approach
- added filter for not caching xhtml (JSF view) requests

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