Bug 141959 Changing data set didn't clean old column bindings
Steps to reproduce: 1.Add two data sets, "ds1" and "ds2" 2.Add a table, binding with "ds1". All "ds1" column bindings generate automatically, that's good 3.Change "ds1" to None Expected result: All "ds1" column bindings should be cleaned Actual result: All "ds1" column bindings are still there. If changing to "ds2", "ds2" column bindings will be added after them.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ColumnBindingDialog.java
getPropertyHandle( ).setStringValue( null );
							commit( );
						}
						catch ( SemanticException e )
						{
							rollback( );
							ExceptionHandler.handle( e );
						}
					}
					else
					{
						combo.setText( getDataSetName( ) );
					}
				}
			} );
		}
		/*
		 * generateButton = new Button( composite, SWT.PUSH );
		 * generateButton.setText( BUTTON_GENERATE );
		 * generateButton.setLayoutData( new GridData( ) );
		 * generateButton.addSelectionListener( new SelectionAdapter( ) {
		 * 
		 * public void widgetSelected( SelectionEvent e ) { try {
		 * generateBindingColumns( ); } catch ( SemanticException e1 ) {
		 * ExceptionHandler.handle( e1 ); } } } );
		 */
		/**
		 * Binding table
		 */
		Table table = new Table( parentComposite, SWT.SINGLE