A Validator is now returned by the AccessTable. It has it's own save
method. The entry.php was split up in entry, edit and revert to separate
the different concerns. Validation is only done in entry and the thanks
to the new Validator mechanism, the once loaded access table is reused
in saving.

This will break all kind of stuff. Fixing that is for the upcoming
commits

this is needed because the object may be reused during testing

This just renames the parameter to make this more clear

* lookups:
  test translation feature
  implement rendering via sub type in Dropdown
  fix displayValue for looked up type, more tests
  fixed constructor signature
  first test for new Dropdown features
  adjusted tests for renamed aliases
  Add Lookup Support to Dropdown
  column aliases need to differ from real column names
  use display value as default renderer
  introduces getDisplayValue