title: CheckBoxTableCell changelistener not working
body: <p>I'm trying to add a change listener to my CheckBoxTableCells but it doesn't seem to be working. I took the example for CheckBoxes figuring they would work the same way. However there is no output when i change its value. How would i add one correctly to a checkboxtablecell?</p>
  
  <p>current code:</p>
  
  <pre><code>tc.setCellFactory(new Callback&lt;TableColumn&lt;Trainee, Boolean&gt;, TableCell&lt;Trainee, Boolean&gt;&gt;() {
                      @Override
                      public TableCell&lt;Trainee, Boolean&gt; call(TableColumn&lt;Trainee, Boolean&gt; p) {
                          final CheckBoxTableCell ctCell = new CheckBoxTableCell&lt;&gt;();
                          ctCell.selectedProperty().addListener(new ChangeListener&lt;Boolean&gt;() {
                              @Override
                              public void changed(ObservableValue ov, Boolean old_val, Boolean new_val) {
                                  System.out.println(new_val);
                              }
                          });
                          return ctCell;
                      }
                  });
  </code></pre>