I would like to add some component, say DropDownChoice, to allow user to change default rows per page setting for data table.
I've investigated two ways: 1) extend NavigationToolbar or PagingNavigator 2) extends NavigationToolbar to add extra panel right to PagingNavigator Althought it is possible to completely override PagingNavigator component it is not so straightforward as I expected. Please improve DefaultDataTable so it will be capable to change rows per page. I also suggest creating child components in all the non-final components via createXXX methods instead of new keyword in order to simplify overriding.
