Add new widget types

Some richfaces components make it possible to provide nicer widgets, for instance:

• tree widget, where you give one xvocabulary (with all the values in the same
  vocabulary entry), with possibility to select any node ;
• autosuggest on a directory (matching some columns while displaying another
  column (or other columns) ;
• filterable drop down : user can start input in the drop down, that filters the val -
  ues in the drop down ;
• between dates" widget (with consistent date control for the given dates)